I've gone back from V9.0a to V9.0 with a largish project, using client-supplied AVCHD files ( 76 of the devils ) and by disabling all thumbnails, which means working "blind" with plain grey thumbnails, I was able to finally complete editing without memory-loss-induced-lock-ups.

However, when I tried to render on Friday evening, it wouldn't go past about two minutes (43 min project) without run-out-of-memory lock-ups/error messages.

Desperation. What to do? V9.0b due in a couple of weeks, but the client wants a DVD in a couple of days.

I tried nesting the project in a new one, as someone posted - this render got a few frames further, then that crashed too. Tried many times with the same result. Felt completely hopeless.

Slept on it. Woke up Saturday morning with a plan .... seems obvious now.

I used V8 to render every single AVCHD.mpg file to Sony MXF.
I then "hid" the original AVCHD files, and re-opened a copy of the project, and when Vegas asked me where the files were, I pointed to the new MXF files.

Anyway, the result is that presently, on Sunday evening, V9.0 is happily rendering ready for DVD.

Hopefully, if I'm ever forced to do another AVCHD project, I shall immediately replace the supplied files this way before starting ....... until a future version really does handle this format efficiently.

Been a good weekend, really.