Gnucash upgrade not working

[Kevin Rutherford]

Hi,
I've been using Gnucash 2.4.x for 6 years and been very happy with it.
But last week I upgraded to Ubuntu 14.04, which brought with it an
upgrade to Gnucash 2.6.1. This new version of Gnucash can read my
accounts file, but for one particular account it won't let me add new
transactions: After I enter the transaction details and press Return,
the new transaction remains open, and I can then do nothing in that
account until I have deleted that transaction.

It does appear that I can enter transactions via the general ledger,
but that's somewhat inconvenient. And of course I have no confidence
that my accounts file remains uncorrupted.

Do any of you have any ideas what might be wrong? And more
importantly, how can I recover the situation so that I can use my
accounts without losing data?
Many thanks,
     Kevin
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