I have an U3-enabled (remember? http://en.wikipedia.org/wiki/U3) USB jump drive (16 GB) which I used extensively between many computers. I also used it on PE w/ Dingo, it was slight delay, but worked plug-n-play. When I upgraded to Ermine, the same drive no longer recognized, however other USBs (not U3) are still work (and recognized faster than on dingo). And if I power PE off with U3 drive and then turn it on again, it gets recognized... This is not a size, as another 16G USB (not U3) works fine on both Dingo and Ermine.