PSQL9 - System Error: 620.0.1450 File: (null)

Hello,

we have installed PSQL9 SP2 Windows Server 3 months ago. Everything
works well. Since the last 6 days we get several times "System Error:
620.0.1450 File: (null)" following a btrieve error 94 in our
application. If we restart the pervasive services everything goes back
to normal until the next error.

We have already interpreted the error as NOT ENOUGH SYSTEM RESSOURCES
while opening.
We have already checked the server but could not find anything wrong.
Also we do not get any errors in windows eventlog.

Server is running Windows Server 2003 SP2 with 4GB RAM

Any ideas?

Thanks in advance

Michael