I got a few of these messages in the "firebird.log" file:

localhost Thu Jan 20 23:45:59 2005
Database: /root/fb/security.fdb
internal gds software consistency check (invalid block type
encountered (147))

when I run gfix -validate, I nothing is pretty to the screen.

If I run isql against the database, then my custom DSQL application
can connect to the database again.

I was wondering what isql is doing to fix the problem.

If I don't run isql after encountering this error, I keep getting
them.