Export Issue - Adobe's Solutions Don't Help

Question

I have an odd problem. I've been using Premiere Pro for a while now, with no problems whatsoever. I have used Adobe Media Encoder to render my projects and haven't experienced anything odd until this morning. I was working on a project that's taken me a few weeks and I tried to render it out so that I could watch it, and I got the following error: "Could not read from the source. Please check if it has moved or been deleted."
I obviously did NOT move or delete the source, I quit the encoder and got out of the project and started again, but to no avail. I restarted my computer, same problem. I looked up the problem (because so many people post on the forums instead of just googling), and I found two solutions - one said that the problem can be caused if I had Premiere CS3 installed and didn't uninstall it before installing CS4. I never had CS3 installed, so that's definitely not the problem. A second solution asked me to put a shortcut named Premiere in a certain folder, and I did that but it didn't help either.
I became so frustrated that I uninstalled the entire Master Collection, ran CCleaner, the CS4 Clean Script, and the CS3 Clean Script (I never had CS3, but just in case the Premiere CS3 thing was the problem somehow). I then reinstalled the Master Collection, and the problem is STILL HERE!
Now for the really odd part - my other projects still render. While I was searching for answers I found that the people the above solutions worked for couldn't render anything, but I can. I'm wondering if there are any file-specifc things that could prevent it from being rendered, maybe it's corrupted or something. However, when I open it it runs just fine, I can watch the entire video playback within Premiere and edit things. Only exporting this one project doesn't work.
I'm running Windows 7x64, 4gb RAM, 2.66ghz quad core. I don't think that information should matter much because other things render, so I don't think it's a hardware problem.
If anyone has any ideas please let me know, I'm desperate for some help!

Answer 1

I've tried that, I can edit the timeline just fine but nothing I do gets it to render. Other things I've tried include only trying to render a small portion of the timeline, and making a new project and importing the entire other project (I thought maybe one of the files used in the project was corrupted, so I thought maybe trying to import everything would give me an error with importing whatever is corrupt. No such luck, it worked fine.)
There is some hope though, I've found two ways to render it based on suggestions from others in other forums on rendering issues - one is to open After Effects, import the Premiere timeline, then render the AE composition because it uses the built-in renderer and not the Media Encoder. A second and slightly mind boggling way is, instead of exporting from Premiere into the Encoder, I can exit everything, open Media Encoder, click File -> Add Premiere Timeline, then navigate to the file and add the timeline to my render queue. When I do it through ME and not Premiere, it renders perfectly. I've already sent that render off to my client with a big thumbs up...but I'm very confused.
I've found a solution for this one, but is there anything I can do differently for next time? It can't be something with the project file if it does actually render...right? Sigh that's 2 hours wasted uninstalling and reinstalling the whole suite