This sounds like an issue that gave me trouble a while ago. You have, of course, done all the requisite Windows 7 optimizations, right? There is one important step regarding USB power management that's easy to miss, in fact it was missing from the first issue of Windows 7 optimizations that I downloaded. Here's the relevant section:
* Open the Start menu and then click on 'Control Panel'.
* In Large icon View, click on Power Options.
* Select the 'High Performance' power plan. Click on the 'Change plan settings' link.
* Set the display's sleep time to Never.
* Set the computer's sleep time to Never.
* Click on the 'Change advanced power settings' link.
* Click on the '+' sign next to Hard Disk.
* Click on the '+' sign next to Turn Off Hard Disk After.
* Select the default; the text entry field will now be accessible.
* In the text entry field, type Never.
and here's the kicker:
* Click on the '+' sign next to 'USB settings'.
* Click on the '+' sign next to 'USB selective suspend setting'.
* Double-click where it says Enabled and click on Disabled.
* Click Apply then OK.
* Click Save Changes.
* Close the Power Options window.
If this step is not taken, Windows will helpfully reactivate power management at the first opportunity, thereby rendering your ILOK inaccessible when you need it most.
Hope this helps
