Wow, a lot of strange issues for sure. For the DigitalFX skin, winamp 5.13 is recommended. NOT the latest version, but 5.13. Check oldversions.com to get that version of winamp.
Make sure you have registered the Winamp.dll file in the root road runner folder. This is what tells RR that you want to use Winamp for the media player inside RR.
Try those 2 things and see if things improve, if not post back, and I am sure we can dig deeper to see what the problem might be.