What can cause a Droid Incredible to stop connecting to a PC via USB? When I connect my phone to my laptop via USB, it is able to charge, but I am not able to mount it as a drive. Neither my computer nor my phone recognize that there is a device plugged in. This happened within the past few days, and I don't think that I changed anything on either side.

I already checked the settings and USB debugging is on, USB debugging notify is on, and Stay awake is on in the Development settings menu. I also tried rebooting both devices to see if that would fix it, but it hasn't.

My phone is a Droid Incredible running CM7.0.3. My laptop is running Windows 7.
Try changing usb cable. Bad cables can cause this (at least I had this problem once, which went away simply by using another cable).