John,

> When trying to export a query with Calculated fields, they export as

Nulls.

> I'm using Delphi6 and IBO4_2ef.

I think it has to do with the TIB_Export component doing a CloneCursor
instead of directly working from the buffers.
Is there a CloneCursor property on your version of TIB_Export and what
happens if you set it to false?
When cloning a cursor I may not be assigning the OnCalculateFields event as
I should be.

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