Mostly when game developers say laptop chipsets not supported, they generally refer to Intel's solutions and at some places via's, since these are the ones most prominent in laptops.
However, this doesn't depend on the chip vender, just the capability of chips. Earlier in terms of compatibility [shader model etc.] laptop chips usually used to be dumbed down versions of their desktop counterparts. Now, however, all chips since Nvidia's 7000 series atleast support Shader Model 3. I'm not sure of ATI's older chips, so I guess a quick google [or bing] search would tell you whether then X1250 supports Shader model 3, and hence most likely AC09.
Also, this info is for the
minimal requirement to run the game, but don't expect quality performance out of a laptop chip in most cases as I said before they are dumbed down versions of their desktop counterparts.
EDIT - I just checked. To cut a long story short, the X1250 only supports shader model 2 at max, so your chances of running AC09 are now next to zero, going by what Rob Walkey said. He said that they're only supporting SM3 now, so your card is now obsolete in regards to this game!
Hope that helped,
Kshitiz