DPC latency issues

[JordanH]

Hi All,
I was debating about whether to place this in the x200 forum or Vista forum as I don't know which it is yet.

I've been having DPC latency issues with my x200s over the past 2 months. The symptoms are...
** This occurs regardless of if it's on wifi or lan-connected.
1. When I boot, the system behaves well.
2. Over time, the computer slows down. Sometimes showing a high CPU usage for simple tasks.
3. using DPC Latency Checker, I can see that after boot, all is well but over time the latency can grow from the acceptable < 1,000 to at least 7 digits.
4. The amount of time that it takes for this issue to present itself is inversely proportional to how much data I've transfered via wifi or lan.
5. At some point the system becomes too slow and the display drive eventually begins to stop responding and tries to restart itself.
6. If leave this to grow even further, BSOD on a miscellaneous task.
7. Using xperf, I am able to view the modules with high latency. In every case they are ndis.sys at the top of the list followed by tcpip.sys and netio.sys.

I have upgraded all of the Lenovo drivers and software packages with the exception of the Intel wifi 5300 v13.0.0000 driver because no matter how I upgrade that driver, the card doesn't seem to work.
** The below is true for installing v13 from ThinkVantage, directly from Lenovo's support site and using Intel's stock driver.
1. ThinkVantage upgrade seems to be applied ok and Windows can see the card but Access Connections won't power it on.
2. Removing Access Connections and Windows can see the card but can't seem to power it on.
Installing the previous driver, v12.4.0.21, allows Windows to both see and power on the wifi card.

I'm stumped. Any ideas on how to resolve the issue? Am I correct in assuming this problem is network driver related? Having to reboot this machine every day or every two days is frustrating.