can't continue my reconciliation

Binary package hint: gnucash

Hello,

My version of Ubuntu:
Description: Ubuntu 8.04.3 LTS
Release: 8.04

My version of GnuCash:
2.2.4-1ubuntu1

I just did my usual monthly reconciliation: I checked almost all cash ins and cash outgoes: then I needed to add some transactions so I exited temporarily the reconciliation window to add them. Then when I came back into the reconciliation window the vast majority of my checks were not there anymore. Only 6 checks were left of 34 ...
As a test, I checked just one transaction, then quitted the reconciliation in the usual manner, and came back into it: my check was lost again. I did a save, exited the gnucash application, re-launched it, then re-did a check in the reconciliation window, to no avail: gnucash does not want to record my checks anymore... I never had any problem with gnucash since two years I use it, until now.
Can you help ?

Jean-Marie