I have to admit to getting a bit nervous everytime we burn one of the Phillips devices !
Calm your nerves, insert a NoTouch boot based on say p2.0 in the startup code (this, of course, makes it a "touch boot") and you can program with FlashMagic regardless of the boot vector contents. For the non-emergency cases you would, of course, base the activation on something else to maintain the no touch.
With Keil, insert a port pin activated NoTouch in the Startup.a51 and you don't give a darn about the boot vector.
The only "problem" is that you have to program the flash the boot vector way the first time you program it, but then never more.

Calm your nerves, have fun

Erik