Hi
The BDM protocol doesn't have handshaking at the lowest level (it is a one-wire connection) and relies on the timing being correct.
When performing a download the success message says that the file was correctly received and copied. It can't guarantie that the device actually programmed. To do this is is best to read back the FLASH.
In your case it really seems as though the BDM is not working or is not connected correctly. It is possibe to verify this before downloading and downloading only makes sense when the connection is known to be good.
1. The target must be in BDM mode. This is entered by performing the reset command on a fresh chip but it is advisable to perform Force Debug Mode since this will ensure that BDM is entered, whatever mode the target is presently running in.
2. Display the internal registers (address 0) to be sure that it is really operational. There is a screen shot of a typical display in the document (note that at one location - 0x22 I think - there is a timer which counts so this will seen to be incrementing on each refresh). Note that it is also possible to see that the device has been forced into BDM mode since the PC always gets set to a 'strange' value like 0x4a4c - I don't remember the exact value at the moment but once you have seen it working you will recognise it.
At this point downloads should then work correctly.
If you can't get into debug mode then you will need to verify that the debug connector wiring is correct. It should have a ground, a reset line and a DBM line. All should be conected to ensure that the background mode can be forced and that the signals are clean. If you can look at the signals with an oscilloscope you can verify that your board is generating them correctly.
I hope you find the problem.
Regrards
Mark