Interbase: Database connection Lost

Hi,

I have a problem. It's a 2tier Delphi project and it's IB Database (GDB
size about 20Mb)
Sometimes occures error: "Database Connection Lost", and Server
Manager->Database Validation
reports " Error .... ". Click on Details - same message (connection
lost).
Using Database shutdown, and many other actions in 20 minutes sometimes
restore DB, otherwise i use
restore from backup and lose day (or 2-3 hours) data.
Such problem :-(
If you can - please help.

Sincerelly,
Anton Kravtsov,
anton...@hotmail.com