When you use a filter like this in IBO it is resolved to SQL instead of
being executed against the client buffers (like the BDE would often do).

You need to use an OnFilterRecord event and have it process the filter there
on the client. This is how IBO allows you to perform filtering on the
records in the client buffer.

It is also possible to use the RefreshFilteredRows (spelling?) to avoid
fetching records from the server again and changing your filtering criteria.

HTH,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com