Wireless Strange Problem!

I m using Win7 on 2 Pcs. On PC1 only Win7 is installed.. PC2 is dual boot with Vista32 Ultimate+Win7 .
My problem is that I hav 2 wifi Dlink adapters....Both work fine in Vista to connect to my Alfa Router....
But in Win7 both r installed, drivers r fully updated,
Both cant connect to Router!!!
.Strange thing is Both Connect to each other IF I create an adhoc connection(btween Vista & Win7 OR Win7 with Win7). but for AP connection windows says "Windows was unable to connect to Network"
I hav tried everything mentioned in this forum from IPv6 thingy to other all possible scenarios.......................
But nothing helped..............
In my router status page Both adapters r present with their MAC addresses...........................................
I Need your help....
Thanks in advance!

Please read the post Wireless Problems