I recommend you read the release notes to know exactly what is changed from
release-to-release.
I did make some changes in the way TIBOTable does a different kind of record
refinement. But, I doubt it is affecting your situation. Since I am doing
only bug-fixes in the 4.2 source base, it is a good idea to keep up with the
latest.

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