I dont have the guts to try the P89v51rd2. The esacademy forum has all scary posts on it. I get all jittery when things come to isp/iap.

If you read these posts carefully, you will see that all the 'problems' are related to not reading the datasheets. The "V" chips are ready for ISP for a short time after reset and then switch to operation. This, of course, require a different technique, but is sooo much easier then "pull this pin high, this pin low, let this pin float ....

So, if you, as, unfortunately many do, just pop in a "V" chip and load FlashMagic and the pull pins, of course it will not work.

Erik