Hmm. Someone else had a similar looking problem in the past (see posts by Mischa in this thread
https://openacs.org/bboard/q-and-a-fetch-msg.tcl?msg_id=0002mP&topic_id=OpenACS&topic=11). Supposedly the problem had been patched. How are you getting OpenACS (i.e. is it a cvs checkout of the development branch or a download of the 4.5 distribution)?
Walter