svchost.exe -k LocalService memory leak, windows 7 64bit

I am running a relatively new installation of windows 7 enterprise 64-bit and am getting intermittent memory leaks in svchost.exe (running -k LocalService). Just to rule out malware/viruses, I rebooted my machine with Kaspersky rescue disk and did a full scan. Zero problems. I've also done full scans with anti-malwarebytes and superantispyware and they only found cookies. So it's definitely not a spyware problem I don't think.

I have only a handful of services running under this PID:

WdiServiceHost - Diagnostic Service Host
nsi - Network Store Interface Service
netprofm - Network List Service
FontCache - Windows Font Cache Service
fdPHost - Function Discovery Provider Host
EventSystem - COM+ Event System

I am pretty sure it has something to do with the networking services. The last time my memory went to 99% utilization, I disabled my ethernet adapter from the network and sharing center and immediately CPU usage maxed out on all four cores and the machine ground to a complete halt forcing me to hard power cycle. In addition, any attempt to stop those services once memory utilization reaches a peak results in either "process didn't quit cleanly within a reasonable time" or "other services are relying on that, you can't stop it" messages (those aren't the exact errors but the next time it happens I will get the exact text)

The onboard chipset for my MOBO is Atheros AR8151 and I tried upgrading the driver from 1.0.0.35 to 1.0.0.45 and that hasn't fixed it.

Here is the file size of svchost:

Code:

C:\Windows\System32>dir svchost.exe
 Volume in drive C has no label.
 Volume Serial Number is 44F5-530F

 Directory of C:\Windows\System32

07/13/2009  08:39 PM            27,136 svchost.exe
               1 File(s)         27,136 bytes

Any help appreciated. It's really annoying to have to come to my machine after several hours of idling and see near 100% memory usage of 16GB and have no choice but to reboot...

Here is a pastebin of the offending process (currently running under PID 1020) from process explorer:

Process CPU Private Bytes Working Set PID Description Company Name procexp.exe - Pastebin.com

That seems like an awfully high number of ALPC ports...

nsi memory leaks fixed yet? - Microsoft Community

Seems to be something that others are also experiencing