Is there any difference between the two chips ?
yes, several, for one the T part has much smaller flash sectors thsn the P part, thus I do not believe that FlashMagic can handle the Atmel part. Also Philips paid for FlashMagic, I doubt they would pay for an Atmel bootloading program.

Let us wait for Andy Ayre to chime in, he comes on here occasionally.

Erik