Always leads to unstable behavior

I've run these cards in 3 different machines (1 x Pentium 4 with XP, 1 AMD Dual Core with Win7 and even AMD Triple Core). Together with a D-Link router it should be an easy thing, but it is not.

I have 3 main criticisms:
a) reach too low, but is probably the DIR-655
b) Time and again unstable under Windows7 already more blue screens.
c) WLAN aborts repeatedly, especially with the DIR-655th

With my old NETGEAR WPN-824 WLAN is more stable, but of course only with 54 Mbit.
Is criticizing Especially that 300 MBit are promised, as well as a much greater range. Throughput, although I could bring up to 10 MB / sec, but the range is disappointing.