Just to make sure all the bases are covered:

The only time I have seen the "internal gds software consistency check
(can't continue after bugcheck)" message was due to an overrun of the
transaction number. This was an Interbase 5.6 Db on Windows NT.

This occurred after running in production for 4.5 months. It then
repeated in another 4.5 months. Somehow during the development cycle
the 4K page database became a 1K page Db without anyone noticing.
Setting it back to 4K and eventually 8K with backup/restores during
the annual outage has kept from reoccurring these last 8.5 years.

- Steve Flanagan