I thought I'd post a solution here in case anybody come surfing by with this problem: :)
I've been having serious problems with rapimgr.exe taking upp 100% CPU time on every startup and the wcescomm.exe not being able to connect or sync.
Just now I tried killing all of my user processes (good way to troubleshoot btw) and found out that it was my FTP-server (FileZilla) that was causing rapimgr to loop infinitely. And indeed, it seems like the rapimgr tries to connect to the filezilla server according to the ftp log file.
*smacks that M$ dev-guy in the face*
Now I'll just have find out how to run my ftp alongside activesync...