Two vendors on one check

[Kristi]

This is so bizarre I can't remember exactly what happened.
Yesterday I was training a sub, Pat, to write checks in Maintain Open Invoices.

Earlier I had written a check to Ellen for $213, but didn't post it.
Pat pulled up Vendor NCPG and entered info in Ref and check amount $48. After we saved it, we noticed it had Ellen and her $213.

We pulled up "locate" and NCPG was not there, Ellen was with the NCPG added to hers. We closed out and re-opened and NCPG was not there.

When I ran a check it was NCPG the correct way.

I ran a journal report for Ellen's check. The information on it is:
Correct check number to Ellen
Bank Account with Combined total $262
line item Ellen $213
line item NCPG $49
Note:NCPG invoice #

Our computer tech happened to walk in the room and told me to re-index and restart my computer.

Any idea what we did, so we don't do it again?
Kristi