The very worst part of using commercial software, contrary to Open Source software, is that you cannot fix it yourself. If a product worked and doesn't work any longer after an update, you are stuck.
Lotus Domino has introduced a so-called "regression" bug in the LDAP task of release 6.5.4 which is documented here. Look at the description to the solution:
This is a regression issue introduced in Domino 6.5.4. The issue has been reported to Quality Engineering as SPR# LORN6FKK9Q, and the possibility of a fix is being evaluated for a future release
The emphasis is mine. What do they mean by "being evaluated"? Don't they feel like fixing it? It is broken! Fix it!