intermittent temporary freezes or pauses on Dell Latitude E4200

I've found some issues with intermittent temporary freezes/pauses on Dell Latitude E4200 laptops. But the hard part is that I've found no rhyme, reason, or consistency for the issue. It's certainly partly hardware related - but how? Here's what I know:

Windows will temporarily freeze every 5 to 10 minutes for 2 to 4 seconds. Keyboard and mouse will be unresponsive and the whole OS seems unresponsive during these short periods.

This problem ONLY happens when docked.

Twice, I have been able to narrow this problem down to hardware. In one case, a locally attached (via USB) Laserjet 2300DN and in another case a Logitech webcam. Once these objects were disconnected, the intermittent freezing stopped.

But I can't narrow it down to specific hardware all the time. For one user, he had nothing but the basics plugged in (USB keyboard, USB mouse, VGA monitor, ethernet). I got a different USB keyboard, USB mouse, and a different monitor (DVI this time). I also updated his BIOS and all other drivers. No effect. The intermittent freezing continued. I've seen this issue before and after the installation of Windows 7 SP 1 and with Symantec Endpoint Protection (separate rant on SEP forthcoming in a future blog post) and with MS Security Essentials.

I'm about to troubleshoot this again on another laptop. Interestingly, I've found this issue on 5 different Latitude E4200 laptops out of about 20 I have in place at various clients. So it's clearly not a universal issue. It's hard to troubleshoot because I have laptops with the exact same configuration not giving the same problem and the problem isn't easy to reproduce. If you have any experience with this issue, please feel free to leave a comment.

EDIT - I have resolved this on two laptops just by updating drivers. From the Dell web site, I updated the BIOS, video driver, mouse driver, and WLAN card driver. I'm not sure which one actually did it, but all the drivers should be up to date anyway.

Dell Latitudes and disabled NICs

One thing I've had trouble with off and on is that Dell laptops with Broadcom network cards disable the NIC when you unplug the power cord and a network cord is not in. This can create problems when you have users who work on a wired connection at their office and then take their laptop home and work wirelessly on battery and then bring their laptops back in. When you clod boot a computer, the NIC comes back on, but if the laptop was asleep, in my experience it does not.

Personally, I've always preferred to just disable that power saving feature. The Broadcom applet in the Control Panel doesn't do it, so I have found the best way to do it is to do this:

Unplug the network cable
Unplug the power cable
For about 3 seconds a Broadcom window will come up that will say "your internal network card has been deactivated. Click here to change preferences"
And then you tell it to "always activate on battery"

You can do this in the dock or not in the dock.