X220 Tablet Sleep issues

[allenkarns]

We are having an issue with 170 - X220 tablets we purchased where they will power off when in sleep mode. The student will close the lid, go to their next class, open the lid and it will restart to the screen saying windows was shut down improperly. It only happens to machines that we installed the battery slice on and we have updated to the latest bios and it did not seem to resolve the issue at all. We are using a a standard windows 7 32 bit image without the lenovo power manager. Any help would be appreciated. 

Thanks

[mludwig]

I would check the event log in Windows to see what does it have to say about the sleep and unexpected shutdown events.