cubase 5 device setup problem

I have been using my roland td-11 electronic drums with cubase 5 for a while now, but today i tried recording while looping my song (not on midi merge mode).
I have’t thought it will be a problem for my computer to run it, but after a while the software crushed, and now whenever i choose td 11 as the driver at the driver setup menu it display the “cannot find a device. please connect the device” message and sometimes crush, Although it can be used as a midi device, and it works fine if i want to listen to other music from the computer through the drums, so i don’t believe it is a driver problem, and i am kind of hopeless.
thanks for your help.