deleted reconciled transaction - now what?

[kevin]

I'm trying to convert from quicken to gnucash - 

I hav entered a few months worth of data and started reconciling
accounts - I had good success until I deleted the wrong duplicate
transaction after reconciling accounts - now I can't seem to get back to
a good starting point for the next months reconcilation - The starting
balances are off  - what is the best way to fix this?

The problem came from importing checking account data and credit card
data - each import had a copy of the same transaction, and so I had 2
payments from the checking to credit card, but they were not flagged as
duplicate during import, after reconcile I deleted the copy which was
not marked as reconciled  - any help welcome