ive had the java error, only when removing an app and letting it restart. then battery pull soon fixed.
ive never had java errors when i do a battery pull with powering off.
from what ive read i *think* that doing it that way just resets it, whereas without powering off, so your in the middle of using it, and pulling the battery can cause data loss.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."