Although the A630 fanatic Lierbag will certainly tell you otherwise (the guy who most probably will be buried with an A630 card as his last dieing request), A630 simply does not work reliably with WHDLoad and this is also covered in WHDLoad FAQ, if you take a look at its homepage.
There could be a particular revision of A600 motherboard that is more compatible than others, however I have yet to find it.
:-)
