I was also suffering this problem. (Host OS is Win7 x64)
In my case it was the Google crash handler causing it.
To find out the cause:
1) Open msinfo32.exe
2) Browse to "Software Environment / Running Tasks"
3) Sort by "Min Working Set"
4) If the top item has an unusally large value then try disabling that process (The largest on my system now is dwm at 51200, GoogleCrashHandler was over 4000000).
To disable GoogleCrashHandler:
1) Open Chrome
2) Go to address: chrome://settings
3) Choose the "Under the hood" section
4) Untick the "Automatically send usage statistics and crash reports to Google"
5) Reboot (May not be necessary - I just did it to make sure)
Hope this helps someone else.
Regards
Rabbit
Message was edited by: Rabbit80 Reason: Typo