I have a SanDisk CruzerMicro 2GB with ReadyBoost enabled. The first time I plugged it in, Vista recognized it and gave me the options of how much space to devote to ReadyBoost, etc. Pretty much it enabled it for me and it worked. The next time I tried to plug it in, Vista only recognized it as a flash drive and didn't give me the option of activating ReadyBoost. I went into the folder and it has a ReadyBoost cache file (.sfcache).. So how do I get it to work?
http://www.sandisk.com/Retail/Default.aspx?CatID=1249 This might help... Mine works every time... so, I don't know. I have the 1 gig.
I am not sure but its possible that you only go through the ready boost setup once and then when you plug in your drive into the computer it automatically uses it for readyboost with the options you specified earlier... Tried deleting the cache folder from the drive or re-formatting it and I bet it will ask you for the ready boost setup the next time you plug it in. I tried it a few times but it doesnt make any diff for me since I have 4gb of ram already.