Bizarre USB issue with Imac

Hey, I just found this resource (mac forums) after having my imac for a year and I am quite glad to have found it!

Anyway, I am having some issues with my imac's usb port.
Firstly, I have a 2.66 core intel imac which is about a year old.
Here is the problem, if I plug a usb device, whether it be a ipod, usb device, mouse or Keyboard, after the computer has booted up then none of the devices are read. However, if I plug the devices in when the computer first boots up, then everything works fine. the Ipod works, the mouse works, etc.
So for example, if I were to boot up my computer with my ipod plugged into my usb port, my mac would recognize it. If I were then to unplug the ipod and re-plug it, the computer will not recognize it. Even in Disk Utility the computer will not recognize it. Furthermore, I have tried every USB port on my computer (3) and all of them have this problem.
Now there is one exception to this strangeness. If I plug in my camera through usb after the computer has been booted up it works fine and I am able to download the photos onto iphoto.
I know its not a Ipod issue as it does this with all three of my ipods and all my devices (except for that camera USB) and I can't think why the computer would be doing this. Maybe a bug?
I looked around on line to see if anyone else had this problem and it looks like I am the only one.
I wonder if I should take it back before my warranty is expired.

Any help would be greatly appreciated.
Glad to be part of the forum.
Micmac

micmac said:

If I were then to unplug the ipod and re-plug it, the computer will not recognize it.

Click to expand...

Whoa, just a minute, are you ejecting the devices you've mentioned before trying to reactivate them, or simply pulling them out of the USB socket (in which case you should get a warning)? Under the MacOS, you must eject all USB devices (from Finder), wait about 15 secs (MacOS is soooo precious about letting go) and then remove the device.

I think the reason the camera behaves differently is that it is self-powered, not bus (USB) dependent.

Take it on in to Apple before your warranty expires. As long as you're properly inserting and ejecting the devices, the USB ports should pick them up regardless if the machine is first booted or not. As for the camera, hughvane is probably correct since it's very likely battery powered and does not depend on the USB port power.

Regards.

Sorry, I totally eject the device before I pull out USB device. But when I plug it back in, lets say its my ipod, the ipod screen goes into the mode that it is plugged in and being recharged, but the computer doesn't recognize it.



Cheers!
Micmac

Just one step before taking up chsag's suggestion, how long is it since you did any maintenance on the OS? In your situation I'd at least run OnyX to repair permissions and execute maintenance scripts. See what eventuates after that.