Right now I finished configuring my blacklist.txt and everything works, but the ignore-groups doesnt. I put ignore-groups=Admin and my Permissions 3.1.5 group is assigned to Admin yet I still can't use the specified items.

WorldGuard Configuration Report
Generated 2011-08-09 21:17 -0700

Version: 5.2.2

Server Information

Java : Sun Microsystems Inc. 1.6.0_26 (http://java.sun.com/)
Operating system : Windows 7 6.1 (x86)
Available processors: 4
Free memory : 45 MB
Max memory : 1017 MB
Total memory : 208 MB
Server ID : unnamed
Server name : Unknown Server
Implementation : git-Bukkit-0.0.0-945-g73697a4-b1000jnks (MC: 1.7.3)
Player count : 0/8

Plugins

Adminium : 1.1.0
AutoMessage : 1.5
AutoSave : 1.3.0
BorderGuard : 3.1
CommandBook : 1.5.2-customized
Essentials : 2.4.1
EssentialsSpawn : 2.4.1
FalseBookBlock : 0.85alpha
FalseBookCart : 0.85alpha
FalseBookChat : 0.85alpha
FalseBookCore : 0.85alpha
FalseBookExtra : 0.85alpha
FalseBookIC : 0.85alpha
GlobalShop : 0.5.2
HeroicDeath : 1.8.1.156
iConomy : 5.01
JSONAPI : 2.0
Lottery : 0.5.0
mcMMO : 1.0.49
MobBounty : 4.05
motd : 1.0
NoMovedTooQuicklyKick: 1.1
OpenInv : 1.3.1
Permissions : 3.1.5
PlgEssentials : 4.6
SpongeRestore : 0.9.8
StealthLogin : 1.1.0
SuperPowers : 0.75
uQuest : 1.5
VanishNoPickup : 1.8.1
War : 1.6 (de Gaulle) PREVIEW 2
Whitelist : 2.7
WorldEdit : 4.6
WorldGuard : 5.2.2
xAuth : 2.0b4
iChat : 2.3.2-p3
LWC : 3.2
MobArena : 0.93.4

Worlds

world (0):
Information:
ID : 5654602195306953934
Environment : NORMAL
Player count : 0
Entity count : 35
Loaded chunk count: 384
Spawn location : Location{world=CraftWorld{name=world}x=425.0y=73.0z=229.0pitch=0.0yaw=0.0}
Raw time : 35824360
Entities :
CraftZombie : 6 [0.015625]
CraftCreeper : 7 [0.018229]
CraftSkeleton: 9 [0.023438]
CraftSpider : 1 [0.002604]
CraftWolf : 1 [0.002604]
CraftCow : 4 [0.010417]
CraftPainting: 7 [0.018229]

Global Configuration

Configuration:
suppressTickSyncWarnings: false
useRegionsScheduler : true
activityHaltToggle : false
autoGodMode : false

World Configurations

world (0):
Information :
Configuration file: C:\Users\Justin\Desktop\MINECRAFTBUKKIT\plugins\WorldGuard\worlds\world\config.yml
Blacklist file : C:\Users\Justin\Desktop\MINECRAFTBUKKIT\plugins\WorldGuard\worlds\world\blacklist.txt
Regions file : C:\Users\Justin\Desktop\MINECRAFTBUKKIT\plugins\WorldGuard\worlds\world\regions.yml
Configuration :
CONFIG_HEADER : #

WorldGuard's world configuration file

This is a world configuration file. Anything placed into here will only

affect this world. If you don't put anything in this file, then the

settings will be inherited from the main configuration file.

If you see {} below, that means that there are NO entries in this file.

Remove the {} and add your own entries.

    opPermissions                 : true
    fireSpreadDisableToggle       : false
    enforceOneSession             : true
    itemDurability                : true
    classicWater                  : false
    simulateSponge                : true
    spongeRadius                  : 2
    pumpkinScuba                  : true
    redstoneSponges               : false
    noPhysicsGravel               : false
    noPhysicsSand                 : false
    allowPortalAnywhere           : false
    preventWaterDamage            : []
    blockTNT                      : false
    blockLighter                  : false
    disableFireSpread             : true
    disableFireSpreadBlocks       : []
    preventLavaFire               : true
    allowedLavaSpreadOver         : []
    blockCreeperExplosions        : false
    blockCreeperBlockDamage       : true
    loginProtection               : 3
    spawnProtection               : 0
    kickOnDeath                   : false
    exactRespawn                  : false
    teleportToHome                : false
    disableContactDamage          : false
    disableFallDamage             : false
    disableLavaDamage             : false
    disableFireDamage             : false
    disableLightningDamage        : false
    disableDrowningDamage         : false
    disableSuffocationDamage      : false
    teleportOnSuffocation         : false
    disableVoidDamage             : false
    teleportOnVoid                : false
    disableExplosionDamage        : false
    disableMobDamage              : false
    useRegions                    : true
    highFreqFlags                 : true
    regionWand                    : 287
    blockCreatureSpawn            : []
    useiConomy                    : false
    buyOnClaim                    : false
    buyOnClaimPrice               : 1.0
    maxClaimVolume                : 30000
    claimOnlyInsideExistingRegions: false
    maxRegionCountPerPlayer       : 7
    antiWolfDumbness              : false
    signChestProtection           : false
    removeInfiniteStacks          : false
    disableCreatureCropTrampling  : true
    disablePlayerCropTrampling    : true
    preventLightningFire          : false
    disallowedLightningBlocks     : []
    disableThunder                : true
    disableWeather                : true
    alwaysRaining                 : false
    alwaysThundering              : false
    disablePigZap                 : false
    disableCreeperPower           : false
    disableHealthRegain           : false
    disableMushroomSpread         : false
    disableIceMelting             : false
    disableSnowMelting            : false
    disableSnowFormation          : false
    disableIceFormation           : false
    disableLeafDecay              : false
Blacklist     :
    State          : Enabled
    Number of items: 26
    Is whitelist   : false
Region manager:
    Type             : com.sk89q.worldguard.protection.managers.FlatRegionManager
    Number of regions: 10
    Global region    :
        Status: UNDEFINED

END OF REPORT

Groups tend to be broken in a lot of permissions plugins. I suggest using ignore-perm instead (and assigned whatever node you choose to the group.)
edit: I recently heard (not confirmed) that Permissions 3.1.5 is (randomly?) returning null for getGroup(s?), which would explain why it's still working for some people