Hello,
I had the same problem with my TWR-S08DC-PT60. I couldn´t use the debugger after the first flashing. I reprogrammed the PT60 with an USB-Multilink and after that the OSBDM worked. .
My PT60 board has the OSBDM Firmware Build 90 Revision 9. That seems a litte strange. I have a TWR-S08UNIV, wihich has Firmware Build 30 and Revision 21, this is the latest Download from P&E. This board has problems with OSBDM too.
You can enable console logging for the debugger to see what is going wrong. When I try to debug my S08UNIV, sometimes the initial connetion goes wrong and sometimes after flashing the device the connection after the reset cant be established.
Eckhard