So, I need some help. I shot AVCHD clips PH 1080P 24P transcoded with the Panasonic transcoder into MXF files to my desktop. Imported that folder with 15 clips into Premiere and and began editing about a three minute sequence in a P2 1080 24p preset. i even interpolated all my files to 23.976 I built a timeline. Everything looked great and played nicely.
Then I went to export it. I Went to file export - media. It launched the media encoder and showed up in the box. It said "waiting." I clicked on start que. When I clicked on that it said loading "my project file" below. After about ten minutes a yellow yield sign came up and said couldn't locate source material.
did you have Pr CS3 on the same system which you had un-installed after installing Pr CS4? If yes, then you may need to re-install Pr CS4 again.
If not, then you can try launching AME, going to File>Add Premiere Pro sequence, navigate to the location where the Pr project is saved and select it. Once the Pr project loads in UI, select the appropriate sequence and click OK and then click Start Queue.
Also, you might want to update to Pr CS4.0.1 and AME CS 4.0.1 and see if the problem goes away.