I am having the same exact problem – I have CS3 PP and it gets “stuck” rendering on the export at 99.96%. I tried cleaning the media cache but am still having the problem, and also deleted all temp files. I’m exporting as H.264, and as a side note, awhile back when I was using the V 2 pass, it was getting stuck, but when I switched to 1 pass, there was no problem rendering…until now. Any advice?