Never mind, never mind. It turns out, the download link for 1.95b was broken for a day or two after it was released, and 1.95 was being distributed. I had assumed that "1.95" had been silently updated to 1.95b or something silly. (like Eloraam does, she sometimes silently hotfixes her mod without changing the version number)
java.lang.NegativeArraySizeException
at ic2.platform.NetworkManager.onPacketData(NetworkManager.java:205)
at forge.MessageManager.dispatchIncomingMessage(MessageManager.java:432)
at adl.a(NetClientHandler.java:1246)
at ee.a(SourceFile:46)
at lg.b(NetworkManager.java:343)
at adl.b(NetClientHandler.java:68)
at je.c(SourceFile:50)
at net.minecraft.client.Minecraft.k(Minecraft.java:1867)
at net.minecraft.client.Minecraft.x(Minecraft.java:819)
at net.minecraft.client.Minecraft.run(Minecraft.java:747)
at java.lang.Thread.run(Unknown Source)
Unfortunately, I can't tell which IC2 machine is sending the packet. I know it depends on rapid movement near the affected area. By rapid I mean sprinting.