Vibrate without notification?

[cronimi]

Since the 4.1JB update on my phone (Droid Razr), every so often my phone will start vibrating. It does a short-long-short-long-short-long pattern about every 3 1/2 minutes. There are no notifications, and I have not established that pattern for any app/notifier. It continues even if I change from vibrate to ringer. The only way to stop it is to reboot the phone. Once rebooted, it seems to be fine for a day, maybe more. Then it'll start again, necessitating a reboot.

Other than continually rebooting (which I know can be helpful, but it isn't always an ideal time to do it), any ideas on a solution?

 

[patruns]

Do you have gmail going to the spam folder?

 

[cronimi]

I don't know what you mean. Some mail goes to spam, that which gmail filters out. But not all mail goes to my spam folder. And gmail is set to not vibrate, so it isn't a notification that mail is in my spam folder. Plus, I don't think my receiving spam could be that frequent/consistent. Once it starts, it literally happens every ~3.5 minutes until I reboot the phone.