Hey Guys,
I have been having a lot of problems with my 6235 card. Connection would drop sporadically and sometimes the only way to bring it back up would be disabling the network adapter and re-enabling it again. The only solution for me at that time was to disable N mode. That solved the issue but completely defeated the whole point of me buying this card.
Today, I downgraded my Centrino drivers to 15.3.1.2 version that came out in September of last year. So far I have been running for a few hours with no problems with N mode. I have been doing some heavy downloading and so far it haven't dropped once. I have also confirmed through my AP that I am in fact running in N mode 2.4ghz.
I have Sager NP9130 running Windows 7 64bit Pro.
Good luck.