The FileConnection.list() (should return list of files/directories under the current one, which is the root when the crash occurs) call on the first root ("Phone memory") found causes phone shutdown. No exceptions thrown, the screen just fades to black and phone powers down. We verified this by writing log messages into a file after each line. The code executes fine on both the Sun's wtk emulator and Nokia's own midp emulator.
We tried this on 2 separate 6630 phones, their firmware versions being: