Phone charges via wall charger but not computer

[Yes]

I have an LG enV3 (http://en.wikipedia.org/wiki/LG_enV3_%28VX9200%29) phone, and it no longer charges when connected to the computer via USB. However, when it's connected via USB to a USB to wall outlet adapter it charges fine. Can anyone think of what the problem might be?

Thanks!

[Hakunka-Matata]

Something similar happened to me with my older blackberry. Turns out newer release ubuntu - I think 10.04 is smart enough to know that the phone is already charged up, and if it decides the phone doesn't need more juice, is don't give it!

But when my phone battery discharged even a little bit, the OS kicked in and started charging.

[Yes]

I should have noted that, sorry - this happens regardless of the OS, Windows XP, 7, or Arch Linux. And up until a couple days ago it charged perfectly fine when I plugged it into the computer.