This issue in 9.0d has been killing me. Shooting Canon HV20 HDV and using Cineform’s Neo Scene and codec for 24p extraction.
What really hurt was that I was editing a film this weekend for the DC 48 Hour Film Project this weekend. Load times for my master project were so bad that overall consumed several hours and kept us from doing a lot of the work we wanted to in post-production (basics like sound mix and color correction, sadly).
Working again today, I found the following link from the Cineform forums:
https://www.custcenter.com/cgi-bin/sonypictures.cfg/php/enduser/std_adp.php?p_faqid=4558
Even though this note refers to 9.0a, I replaced the avi DLL in my Vegas 64-bit 9.0d installation. Lo and behold, and fingers crossed, but the difference is night and day. Projects that were taking 20+ minutes to open, now open in one to two seconds. And far less memory usage (and no paging, which makes me suspect the bug in 9.0d is a runaway memory leak).