Vista ready-boost function…

I’ve been looking around for a way to disable Vista’s ready boost feature. All I have come up with are recommendations against doing so.

Is it possible to do this without crippling the system, and if so how do I go about it?

It is causing me some problems related to a large flash drive that I use for work related purposes. Vista will not shut off the drive, whether I use the icon in the system tray for safely shutting down hardware, or whether I use the feature built into the flash itself. I have to shut down the computer to turn off the USB port. I do not get any dialogue box when plugging in the drive, Vista just automatically uses it as swap file. At least I think this is what is going on. OS Win Vista Business Edition.