Anigozanthos

I've just recently purchased my first laptop, a Dell Inspiron 1520. Actually, two of these were purchased at the same time, with the second going to a work colleague.

Soon after taking delivery of his, my colleague complained about the keyboard regularly becoming non-responsive. I had a look and found that while you typed, the entire computer would become unresponsive, with keystrokes slowing down to about one every second, even while holding down the keys.

Whatever the problem was, it wasn't a process going nuts, because if I kept an eye on the Task Manager process list, nothing would ever show up - it always reported the machine as mostly idle. So no clues there.

What made it weirder was that my identically configured laptop didn't have the problem. Booting into safe mode made the problem go away, confirming it to be a software rather than a hardware problem. The real question was - what?

We started by uninstalling applications. Eventually we had uninstalled all the software installed after it was received, plus a good amount of the pre-installed stuff, but no relief. We moved on to System Restores, eventually going back to the earliest possible restore point. Nothing. Finally we gave in and reformatted and reinstalled Windows. The problem was gone!

Still having no idea what the problem was, we started reinstalling drivers, updates, applications, and transferring settings. After one set of reinstallations the problem returned and we realized we'd committed the cardinal sin of troubleshooting - not doing one thing at a time and testing after each step.

Reformat, reinstall, update. This time we checked after Windows reinstalled, after each device driver was put on, and after each Windows Update. Nothing. Next we installed all the applications. Nothing. We'd brought the laptop to the point where everything was installed, but no data had yet been transferred.

The email accounts were restored (into Outlook Express 6 - remember, this isn't my computer!), then the contacts. Bingo!

To confirm what we'd found, we cleared out all the contacts. Problem gone - the keyboard operated perfectly. Re-import the contacts - and the keyboard started stalling. If I wasn't sitting in front of the machine doing the troubleshooting, I wouldn't have believed it.

Since the contacts were just in a CSV file, I made up a fake contacts file, with a simple contact pre-built with just a name and email, differing by just a number (i.e. "contact00@foo.com", "contact01@foo.com", etc.). I started by importing a set of 10. The keyboard problem appeared, but only a little bit. Then I imported a set of 100. The keyboard problem appeared, in a big way! The more contacts there were, the worse the keyboard stalling became.

The final proof was importing the made-up set of contacts directly into the Address Book on my previously trouble-free laptop. The keyboard started stalling. Delete all entries - no more problems.

I then tried it on my desktop machine - no problems. It would have been interesting to reformat the laptop and test the Address Book immediately after installing Windows, before any updates or Dell device drivers and software had been installed. It takes hours to re-setup a machine, though, and I've already done it three times. No way I'm doing it again.

This would have to be one of the weirdest problems I've diagnosed. Previously I would have said there's no way the Address Book could create such a system-wide problem as the keyboard stalling. It's all part of the magic of modern computing.

I'm just happy I figured it out.

PS. Keep on reading - the real solution is in the comments...