I believe i might have the same problem as you. i plug my iphone in the USB port and the computer makes the bling noise as if it connects to the computer but usually the iphone would say its charging but it doesnt anymore and the computer doesnt detect the apple mobile device. When i plug my ipod in the computer it works and when i plug my iphone in another computer it works. Its just the connection between my iphone and the computer it is synced to. I was told this might help me but it didnt so maybe it will help you.
Verify iPhone Driver/Service Installation
iPhone requires two important pieces of software to operate properly on Windows. First, the driver must be installed; for iPhone the driver is USBAAPL.SYS. Second, Apple Mobile Device Support must be installed as a Windows Service. If these are not installed, see the Reinstall iTunes section below.
Verify that the driver is installed by connecting iPhone to the computer and following these steps:
On the Start menu, click Run.
In the Open field, type
devmgmt.msc and click OK. A list of devices will be displayed.
Scroll down to +Universal Serial Bus+ controllers and click the small plus sign to expand this group. iPhone will be listed as either +Apple iPhone+ or +Apple Mobile Device+ depending on the version of the driver installed.
Right-click Apple iPhone (or Apple Mobile Device) and choose Properties from the shortcut menu.
When the Properties window opens, select the Driver tab.
Click Driver Details to view more information.
Verify that the Apple Mobile Device Service is installed and running using the Services MMC snap-in using these steps:
On the Start menu, click Run.
In the Open field, type services.msc and click OK. A list of devices will be displayed.
View the list In alphabetical order and verify that the "Apple Mobile Device Service" status is "Started."
If the status does not indicate the service is started, right-click Apple Mobile Device Service and choose Start from the shortcut menu.
If the service is installed and started, right-click the service and choose Restart from the shortcut menu.
If the driver is installed and the service is installed and started, check the Event Viewer for error messages.
On the Start menu, click Run.
In the Open field, type eventvwr.msc and click OK.
For more information on viewing or interpreting event logs in Windows, see Microsoft Knowledge Base Article 308427, "How to view and manage event logs in Event Viewer in Windows XP."
I hope that made sense to you, i copied and pasted. Hope this works for you, i didnt work for me.