> The problem is, that we have an (increasing) amount of
> errors/problems regarding to other applications that are also using
> the firebird/interbase server.

Other applications on the same Server should not cause any problems -
at least if the server is not yet overloaded.

> Some of them use different versions of the server, some are running
> with a local server installation, some use modified
> sysdba-passwords,....

"modified" Paswods for SYSDBA are the usual case - you should never
expect your client to have "masterkey" there.

Using different Versions might be an problem, you should specify what
Version to use - mayby your application should refuse to work on other
Versions. Your application should have the ability to connect to
DB-Server listening on an different port. This does enable installing
an additional instance if required.

> Last but not least our software can be used single- or multiuser -
> with or without a dedicated server.

You can have an server running on the workstation.

> - We don't need to run the firebird "clientsetup" on every
> client.

In most cases this can be prevented by using the renamed DLL - the
registry-items should be superflous.

> Does anybody know if this should work under all possible conditions
> or does anybody know that it could/should fail? What about Win98 (a
> lot of our customers still use it)?

Windows 98 should be ok in general - I'm using it for myself. For any
reason I went into trouble loading an "fbintl2.dll" with an customized
collation order: Both embedded and superserver did ignore the file on
Win98se - NT4 was able to utilize it.

Elmar