Treo 650 IMAP with Versamail 3.0c - Cingular - GW 6.5.4

User reports:

1) sometimes it hangs up on "connecting" or "sending" and I have to turn it
off, pull the battery, and do a reset

2) sometime it shows the send as having been completed, but nobody gets my
email (I tested it on myself)

Does anyone have any ideas about what the source of this problem might be?
Hardware, software, network? Thanks,