uh oh...miche hubs...i'll share with you one of my experiences along the same lines.
When I was still living in philly, I was going at a pretty good clip up 13th st towards race (turning right on race toward 6th) I turned to corner, still pretty much flying...and i hit the ground...(little difference, but here's the important part) i hit the ground on my right pocket (u lock pocket, at the time) slid LITERALLY 30 feet down race, over to the far curb. I stopped right before the curb and went "SAFE" (with the correct baseball umpire arm movement) there was a lady cop standing back at the corner...she asked if i was ok and said there was nothing in the road..

I determined the culprit to be my cones...The ones on my hub. I always had one hell of a time keeping them tight on my miche hubs. I don't see why that should affect you going in a straight line, but if you were rocking your bike, i could see it. I'd check 'em. Also, you didn't catch your seat on your ass did you?

-jason