RE: Insert Subform caused Notes 6.5.4 designer to crash Andre Guirard 2.Jun.05 10:55 AM Lotus Notes Domino Designer 6.5.4Windows XP
This sounds like SPR# ZHZH69QBRL, which I recently fixed for 7.0. It will probably be assigned to me for 6.5.something. It seems there's a problem inserting subforms that contain event script in their fields. If this is not the case for you, please contact support.
For the moment, you should be able to work around the issue by using a computed subform with a constant formula.