I had a DV 24P project go into what I call "rendering freeze" - it opens up the render box, but then does nothing. It will simply sit there for hours if I let it, but I can escape out of it at any time. The project was a CS3 import that is 95% done, and my deadline isn't until March, so I set it aside for more pressing work. I'm on Vista Ultimate and CS4 has been rock solid for me on multiple projects, from scratch and CS3 imports.
(under "render details" it shows the start time correctly, but both the "time elapsed" and "free disk space" fields are blank)
Tonight I started a new 1080 HD1080P 24 project, and a few renders into it the same thing happened. I thought this would be a good opportunity for troubleshooting, since I had little time invested into the project.
I tried deleting effects, tracks, then assets, and finally everything to see if I could get a render to work. Dead. I tried opening a new sequence and importing a simple jpg as an asset. Same problem. I tried it over again using DV and other sequence timelines to see if it was format dependent. The freeze seemed to be project independent.
I started over with a new project using the same format, assets, and effect, duplicating the same steps as as closely as possible, and rendering continues to work fine - and I'm much further into the project. This has me scared to death that my DV project (the one that is 95% done) is nearly useless (the 5% left to do is all detail work and must be rendered to check edits).