The below was not the only reply, but as Gerhard chimed in with a
similar problem; I will include this post and reference the others.

1) without noting it, I had already eliminated as the problem:
* We don't use TTables at all, never have
* LAN/Internet -- the problem presents over both
* DNS Forward and Reverse Lookup -- the name resolves and connections
are fast -- disconnects are our problem
* backup/restore
* mismatched driver version (5.6 <> 6.01) -- thanks Henry, we found
this one shortly after 6.01 came out (what a bugger that was)

2) I will second Alan's question about serious problems with v6.01 --
what are you referring to, Aage?

3) This app was in top shape before upgrading our dev server to
Windows 2000 AS/AD/SP3 and reinstalling Interbase. Also, the server
has been running in the field for years now on NT, NT TS, 2K, 2K AS
and we have never seen this problem. So the suggestion about "this is
what you get..." is off-base.

4) I have stopped these services and the problem seems to have
disappeared. Put another way, it was consistently misbehaving prior to
these services being stopped:

File Replication
Distributed File system
Application Management
FTP Publishing Service
Logical Disk Manager Administrative Service
Simple Mail and Transport Protocol
Simple TCP/IP Services

ANSWER?) Ok, I'm going to blow it and give you guys my *guess* -- I
think the problem may be in a similar vein as the System File
Protection problem in XP, ME. I wonder if fresh Windows 2K AS, Active
Directory, SP3 applied starts a combination of things that cause a
file to be backed up or otherwise processed after it's been closed --
hence the problem on disconnect.

With those services above disabled, the problem goes away. Some of
those services look suspicious to me, in that they may be hooking into
creation/updating/deleting files to do their job. Am I getting warm?
any takers on that theory?

>KevinHerrmann wrote:
> > Recently, our app using Interbase v6.01 began to get S-L-O-W on
> > disconnect. I have checked google web and groups for help but came up
> > with something similar that seemed to fix itself.
> > ...

> Are the disconnects slow on the LAN as well?
>
> My first guess would be "this is what you get for using BDE + TTables +
> Internet".
> I've seen slow disconnects, but these were reaaaaally slow - caused
> by a sweep thread kicking in, I assume.
>
> I haven't used IB/6.01 myself (just IB/5.6 and Firebird) - maybe you
> should
> make sure you are using the latest version as early IB/6.01 had serious
> problems.