How do I prevent this scenario?
I have a routine that such as the following.

on error goto errHandler

validation code etc.

.BeginTrans
rst edits etc.
.committrans
exit sub
errHandler:
rollback

Everything is fine unless an error occurs before the begintrans line then my
error handler returns an error because I try to rollback a trans without
begintrans.
How do I handle this?

Dim a boolean value i.e. Dim fTranInEffect as boolean.
Set that value to True immediately after invoking BeginTrans.
Set that value to False immediately after invoking CommitTrans.
In your error hanlder
    If fTranInEffect = true then
        we.rollback
    End if

Good luck,
Doug