transactions

Is there any known issues regarding transactions.
I got something like:

begin transaction
select function1()
select into v1 function2()
if v1='ok' then commit else rollback end if

To notice that both functions have about 100 lines of code.
And both functions uses the same tables but in different modes.
function1 deletes && function2 inserts

The problem is that my web browser hangs on this query and stays that way a lot [like 30 minutes -- i forgot about it and after 30 minutes it was still trying to open the result page]

I hope tomorrow I'll resolv this and if is primary my fault I just shut up and say nothing.

regards,
vioss