Strange ReadyBoost Experience

Today I thought I would try out my spankin' new (ok, new to me) SanDisk Cruzer Micro U3 with ReadyBoost (RB from now on) on my Vista laptop. I disabled RB on the existing drive (a tiny 1 gigger) and removed the device, then plugged the new bad boy in and assigned it the same drive letter as the previous one. (Technically this is skipping when I had to plug the drive into an XP machine to remove the probably-useful but nonetheless irritating U3 stuff but that is ANOTHER story.) After the drive was mounted I noticed that Vista did not prompt me to use RB. A quick peek at the properties for the Cruzer revealed that Vista didn't think the drive met the minimum requirements for use with RB. This seemed strange to me because on the packaging for the Cruzer it clearly says "Enhanced for Windows ReadyBoost." I thought maybe there was something screwed up with the drive so I ran HD Tune and the benchmarks were way above the RB minimums. This was becoming a bit of a puzzler - time to engage the extra brain cells...

Or not. The next thing I tried was changing the drive letter. As soon as it recognized it the RB dialog popped up. FIXED.