Tim, I’m not sure how I missed this, but…
This sounds like you’re just dealing with dead links – the physical file location has been changed since you imported the songs into DEX 3 RE, thus resulting in files that can’t load/play since the links are no longer valid. The most common reason for this is the hard drive letter changed on you, thus changing the path (if you rename the folder the files are in, or rename the files themselves, the links will also be broken).
I realize this is a very old post, and you likely already received support from our techs. Regardless, let me know if you need any further information!