06-26-2014 09:45 AM
You question goes beyond what we may be able to help you with in this forumn. It could be a bad or currupted database or other things. Basic troubleshooting woud be to try against another demo database and to check the import source for bad or garbage data. Try a smaller subset of the data.
You may approach an ACT consultant to help with the merge as many are able to clean up and trouble shoot problems of that sort.
Finally, please consider a newer version. There is much that has been improved over the past 10 years since that version came out.