I gave a clay soldier a gravel block, and the game crashed when he threw it. Here's what came up:

---- Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.

Time: 9/29/14 4:43 PM
Description: Ticking entity

java.lang.NoSuchMethodError: net.minecraft.world.World.func_72933_a(Lnet/minecraft/util/Vec3;Lnet/minecraft/util/Vec3;Z)Lnet/minecraft/util/MovingObjectPosition;
at net.minecraft.entity.projectile.EntityThrowable.func_70071_h_(SourceFile:154)
at de.sanandrew.mods.claysoldiers.entity.projectile.EntityGravelChunk.func_70071_h_(EntityGravelChunk.java:88)
at net.minecraft.world.World.func_72866_a(World.java:2019)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:660)
at net.minecraft.world.World.func_72870_g(World.java:1983)
at net.minecraft.world.World.func_72939_s(World.java:1836)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:501)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Stacktrace:
at net.minecraft.entity.projectile.EntityThrowable.func_70071_h_(SourceFile:154)
at de.sanandrew.mods.claysoldiers.entity.projectile.EntityGravelChunk.func_70071_h_(EntityGravelChunk.java:88)
at net.minecraft.world.World.func_72866_a(World.java:2019)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:660)
at net.minecraft.world.World.func_72870_g(World.java:1983)

-- Entity being ticked --
Details:
Entity Type: claysoldiers.gravelchunk (de.sanandrew.mods.claysoldiers.entity.projectile.EntityGravelChunk)
Entity ID: 442
Entity Name: entity.claysoldiers.gravelchunk.name
Entity's Exact location: -244.69, 4.35, -878.01
Entity's Block location: World: (-245,4,-879), Chunk: (at 11,0,1 in -16,-55; contains blocks -256,0,-880 to -241,255,-865), Region: (-1,-2; contains chunks -32,-64 to -1,-33, blocks -512,0,-1024 to -1,255,-513)
Entity's Momentum: 0.58, 0.03, 0.03
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1836)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:501)

-- Affected level --
Details:
Level name: Modded CSM 1.7.10
All players: 0 total; []
Chunk stats: ServerChunkCache: 625 Drop: 0
Level seed: -6471760539274866638
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (-239,4,-871), Chunk: (at 1,0,9 in -15,-55; contains blocks -240,0,-880 to -225,255,-865), Region: (-1,-2; contains chunks -32,-64 to -1,-33, blocks -512,0,-1024 to -1,255,-513)
Level time: 24336 game time, 4816 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 24776 (now: false), thunder time: 101407 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 8 (x86) version 6.2
Java Version: 1.7.0_65, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 127886816 bytes (121 MB) / 287899648 bytes (274 MB) up to 523501568 bytes (499 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v9.05 FML v7.10.18.1180 Minecraft Forge 10.13.0.1180 13 mods loaded, 13 mods active
mcp{9.05} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
FML{7.10.18.1180} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Forge{10.13.0.1180} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
TooManyItems{1.7.10} TooManyItems Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
bcmod{2.6.4} [BCMod (Brad16840 Core Mod)](zz-bcmod 1.7.10 - 2.6.4.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
sapmanpack{2.0.0} SanAndreasPs Manager Pack CORE edition Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
lucky{5.1.0} Lucky Block Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
backpacks16840{2.6.1} [Backpacks!](backpacks 1.7.10 - 2.6.1.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
blocklings{1.2.0} Blocklings Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
claysoldiers{2.0} Clay Soldiers Mod Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
craftguide{1.6.8.1} CraftGuide Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
ElementalCreepers{4.2.1} [Elemental Creepers](Elemental Creepers-universal_1.7.10-4.2.1.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
TwilightForest{2.3.2} The Twilight Forest Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'

Didn't you see, it was supposed to happen! :P
No seriously, try the updated ManagerPack, you can grab it from here:
http://www.minecraftforge.net/forum/index.php/topic,2828.0.html

So I looked into this issue and yes, it was a bug in the manager pack shipped with CSM. The link I gave you is the updated one, which has this bug fixed.