PC doesn't recognize iphone, will not charge with wall charger, but will with iHome?

hello.

i have an unlocked 2g iphone that i've used without problems for awhile now. a week or so ago, i removed it from my computer around 11am and that night when i went to plug it back in to my laptop (an hp pavilion running windows vista 64 bit), nothing happened, it didn't start charging, the computer didn't even make a noise. so bizarre. i had barely touched the phone all day, it stayed safely in my pocket. i didn't drop it, nothing.

i did quite a few things in attempt to get it to start working:

* first and foremost i obviously restarted my computer - nothing.
* power cycled the iphone (two button reset) - nothing.
* used all three of my USB ports - nothing.
* used another USB cord in all three of my USB ports - nothing.
* uninstalled and reinstalled all USB root hubs - nothing.
* verified 'apple mobile device' was running in services.msc - yes.
* tried to sync my iPOD with usb cord to verify the usb cord works - synced successfully and immediately, no problems whatsoever.
* uninstalled and reinstalled to the newest version of itunes via apple.com/itunes - nothing.
* checked device manager - my computer is not the least bit aware the iphone is there.
* tried connecting to wall charger with three different USB cords - nothing.
* tried putting the iphone in recovery (dfu) mode - iphone shows the picture of itunes icon and usb cord, but itunes does not come up with message.



the only two things that did work:

* connected iphone to ihome - charges successfully.
* connected iphone to car charger - charges successfully.


i'm at a loss here. my first thought was that something was wrong with the iphone's hardware, but if that were true, how is it charging on the ihome and car charger?

any ideas or just your input would be fantastic. i am going crazy here, not just because my iphone is broken but because i do not understand WHY!

thank you.