Good Solution
I was also having a problem with my phone failing to vibrate with any type of notification. I believe this happened after installing Locale, but I could be wrong. After some searching, I found a solution here: the droid geek [dot] com: Android Stopped Vibrating - Fixed. Although it involves installing an app called sound manager, I believe it allows you to fix the problem by controlling the phone's built-in vibration functionality instead of using another program to add additional notifications.
I was also having a problem with my phone failing to vibrate with any type of notification. I believe this happened after installing Locale, but I could be wrong. After some searching, I found a solution here: the droid geek [dot] com: Android Stopped Vibrating - Fixed. Although it involves installing an app called sound manager, I believe it allows you to fix the problem by controlling the phone's built-in vibration functionality instead of using another program to add additional notifications.