Well according to the compatibility list my processor is supported but my processor rated FSB speed is 533 Mhz and the board is rated for 1333/1066/800 MHz FSB so how could it work?
If it's on the list of supported CPUs, then it will work. If it can handle a FSB of 1066 MHz, then it can certainly handle a FSB of 533 MHz. The base frequency is 266.66 MHz:
266.66 * 2 = 533
266.66 * 3 = 800
266.66 * 4 = 1066
266.66 * 5 = 1333