> I use IBO 4.2Hc and Firebird 1.5 in Windows XP SP2

Is it a hyperthreading capable system?
Are you using Superserver?

> I noticed that approximately after 100 records the program
> hangs a minute or more in Post() and then continues.

Annoying delays seem to be a feature of HT enabled systems
with Firebird 1.5 Superserver and prior (not sure about v2
yet). I have seen this problem most often when doing transfers
from one database to another on the same server. The problem
only seems to appear if the connections use TCPIP (even
localhost) and do NOT seem to appear on true windows local
connections.

If this describes your problem...

Option 1. The simplest option is to change to classic server.

Option 2. On a single CPU system disable hyperthreading in the
system BIOS. On a dual CPU system, you seem to be stuck. The
bug does NOT occur on non-HT-capable dual processor systems
but seems to persist on HT-capable dual CPU systems whether HT
is enabled or not - no idea why.

Option3. Experimentation on my dual CPU system seems to give
best results if I leave HT enabled and set the CPU affinity
across all four CPUs. The other alternative seems to be to
have a separate process/thread that constantly "talks" to the
server to keep it awake.

Perhaps your problem is something else, but your mention of
delays in database transfers caught my attention.

--
Geoff Worboys
Telesis Computing