I'm using OpenBlocks 1.2.8, OpenPeripheral 0.4.0 and ComputerCraft 1.58. And then I run ths code (or any code related to the magnet) on a turtle
m = peripheral.wrap("left")
m.activate()
I get a crash report:

Description: Exception in server tick loop

java.lang.AbstractMethodError: openblocks.integration.cc15.MagnetControlAdapter.isValid()Z
at openperipheral.adapter.peripheral.ExecutionStrategy$3.isValid(ExecutionStrategy.java:156)
at openperipheral.adapter.peripheral.ExecutionStrategy$3.isValid(ExecutionStrategy.java:147)
at openperipheral.adapter.peripheral.ExecutionStrategy$OnTick$1.run(ExecutionStrategy.java:103)
at openperipheral.TickHandler.tickEnd(TickHandler.java:52)
at cpw.mods.fml.common.SingleIntervalHandler.tickEnd(SingleIntervalHandler.java:34)
at cpw.mods.fml.common.FMLCommonHandler.tickEnd(FMLCommonHandler.java:141)
at cpw.mods.fml.common.FMLCommonHandler.onPostWorldTick(FMLCommonHandler.java:282)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:677)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:129)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)

Fixed in 5d05f84