Hi Mel
Just a couple of things to clarify what you are saying
You went into pay liabilties in payroll to prepare the child support payment but it got hung up
If you go back into that pay liabilities screen for the same time frame does it still appear?
If yes - just process again
If no and as you say it doesn't appear in the electronic payment file then it may have gone to a different bank account.
Do you know the amount? If you do you could do a search on the amount from banking - find transaction
Alternatively have a look at the general ledger account for child support and see what transactions have occurred.
It may be that the date was also later
Hope these suggestions are useful
Lisa