Intel 5300/5350 Intermittent Wifi Solution - Don't use WEP security!

Question

I recently purchased a Lenovo T400 with the Intel 5350 wireless card (same as the 5300 but with WiMax), and, like a lot of other people on this forum, I could not get the wifi to consistently work. I spent several frustrating days searching these forums and trying pretty much every solution offered (XP 32 bit, Vista 32 bit, Vista 64 bit, w/ & w/out Access Connections, w/ & w/out Intel software, Lenovo drivers vs. Intel drivers, etc.). However, in the end, the solution was totally unrelated.
What I found was that when I was using WEP security on my Linksys WRT54G router (v5 w/ the latest firmware) I could not get wifi to work consistently. In most cases it was hard to get it to work at all. In other cases it might work after a reboot for a few minutes, then stop working again. However, as soon as I either turned off security or changed it to WPA2-Personal, wifi worked like a charm.
I was originally thinking about returning the laptop, since no wifi makes it pretty much unusable. But, with this finding I think I will keep it. Since it is obviously a driver issue, I'm going to assume there will be a driver update in the near future to fix the problem.
Hope this helps some of you who are having the same problems!

Answer 1

That is a fascinating solution to the intermittent mess the Intel cards can go into. Never would have thought secrurity and encryption would affect the performance.
For what it's worth, go into the properties of the wireless card in Device Manager. Go to the Advanced Tab. Set "Roaming Aggressiveness" slider to the lowest, "Power Managment" to lowest, and "Transmit Power" to highest. These were solutiosn that I've run across and fixed the problem for me (I have the regular 5300, hope you will get to use and enjoy WiMax).