Dear Martin,
I've just re-checked using the USBDM-JMxx-CF with a MCF52233 based board and it works fine with Codewarrior for Coldfire V7.2 using the 'latest' DLL. The MCF52233 is the same family as MCF52213 I believe so should be a good test.
Using the TestUSBDM program provided and doing the usual things - setting target 4, RESET, regs, wpc etc seems OK. Lookin in a DSO shows the expected activity on the RSTI lines etc.
The hardware description you have given doesn't sound correct.
RSTI - This should be high unless the BDM is actually resetting the target - offhand I can't remember if it does this when connecting (probably).
RSTO - This should be high since RSTI is not active - The BDM monitors this signal and it being low is the reason for the error message. RSTO may be held low if there are Clock problems on the chip or Vdd is too low - may be other reasons.
BKPT should be 'active' to enter BDM mode - This is active-low signal so I would expect it to be low when the BDM is attempting to connect.
Other signal aren't relevent since they aren't in use at this stage of the connection process.
Can't really suggest much:
Try the coldfire chip without the BDM connected. Does the RSTO signal rise?
Check the BDM w/o the target. Is RSTO high now?
Could you run the setboot command and check that the firmware information reported looks OK i.e. Firmware version = Actual Hardware.
You can use the TestUSBDM command to conveniently try things like 'reset' etc.
bye