I hope I can add to this solution, by describing my simmilar problem. I don't believe for a second that it's related to the LEDs. The reason for that, is that fact that I have had the same problem since the start, and originally I never used the LEDs. Only recently did I start using them, and they didn't seem to make the problem worse or better. I believed it to be a simple issue of screen corruption, that happens to all LCDs, but really it doesn't happen to all LCDs... so just to be clear I too have a 635, currently plugged into a normal USB (too lazy to look up where on the MOBO to plug it in, since im using a brand new Striker Extreme).
Perhaps this should be in another thread, but I have another issue that just came up. I did a windows update yesterday, and it offered me a driver update for my Crystalfontz LCD. I was weary, but it identified it correctly so I let it go ahead. As soon as it installed my system rebooted from a half second blue screen. Now whenever I plug it in, it restarts my machine. All I can remember is that the driver was from March of 2007. I need to replace that driver some how, or something. So if someone can email me a solution, or post it here, that would really make me feel better (i really miss my nice blue display).
The driver issue is being addressed in this thread. -Admin