The weird thing is that my other Win 7 32bit laptop can connect to the same server just fine. I don't know how to check if Java is 32bit or 64bit, but here is the output from java -version:
C:\>java -version
java version "1.7.0_05"
Java SE Runtime Environment (build 1.7.0_05-b06)
Java HotSpot Client VM (build 23.1-b03, mixed mode, sharing)
I have CommandBook, Dynmap, EM - Creeper, Hawkeye, Tree Assist, WorldEdit, and WorldGuard as plugins. How can I figure out which plugin is causing problems?