On the Keil Discussion Forum, I mentioned in passing:

"A word of warning when debugging in uVision:
The values displayed for R0-R7 (in both the Registers window and by typing "Rn" on the command line) are only ever for Bank zero!"

http://www.keil.com/discuss/msgpage.asp?MsgID=2260

It seems that this is actually a problem with the Triscend E5 Driver (te5_uv2.dll) rather than uVision itself.

Does anyone else have any comments/experience on this?