What model of Dell notebook are you using, and is this problem specific to that model? Perhaps it's only on a Latitude XXX and works on other types of Dell Notebook, and then you have something to focus on. Then you could check with Dell and McAfee support to see if there's a hardware driver compatibility issue between the SSO shim and the card reader drivers.
Have you tried to find updated Dell drivers for the card reader that may resolve the issue for you?
Dell Latitude D530,430,420.
I will try to look for driver updates.
Workaround is this problem to disable the device.
I bet they all use a common chipset (USB or reader) or driver on the OS Side. I would also bet that Dell may be aware of this issue. There's too many of those notebooks in use with DLP related shops for them not to be aware of the issue.
It seems there's a lot of posts about Dells and EEPC on this forum. You might find the answer you seek out there. Good luck!