I have been shooting with the Olympus EP1 and since LR does not recognize the files yet I decided to try the new version of the DNG Converter.
It (the DNG converter) recognized the EP1 RAW files fine, converted them and I was then able to import into LR without any problems.
However - if I attempt to open the folder where the DNG files are in using Windows Explorer (or My Computer) - using XP Pro SP3 - Explorer will not show the files in the folder (neither a listing of them or the thumbnails) and trying to change folders will result in a "Not Responding" dialog box. I have never had this problem using any of the Olympus RAW files (multiple different Oly cameras).
Any suggestions (because it is pretty annoying) aside from giving up on DNG and waiting for the LR update?
I'm unable to reproduce the problem. Can you let us know what DNG Conversion options you used and what Lr import options you used? Also, does this happen when you put the DNGs in a different location in your filesystem--for example if you use a folder on your desktop instead of a external drive, etc.