1. drop the RC reset and get a real reset IC (was that you with whom I discussed a Zetex reset IC on the edaboard forum?); ensure a clean VCC (decouple heavily); try the common '51 troubleshooting steps (http://www.8052.com/faqs.phtml?FAQ=120313 , on the bottom)
2. make sure there is no signal at the RxD pin while resetting
3. I have no idea what is Phyton Programmer - any link?
4. the ISP capability is very comfortable, you might want to start to use it now
5. there is a gotcha in the form of SoftICE mode (which can be set inadvertently e.g. by incorrect flags setting in the programmer by the unaware user) - google for "unsoftice" for details

JW

PS. Please use the whole designator, i.e. P89V51Rx2 (replace x for B/C/D as per your chip) - the suffix in this case DOES have a meaning!