I am on what i think is Karmic's newest kernel

arthurb@aetna:~$ uname -r
2.6.31-14-generic

and see the same behaviour. all usb devices stopped working as soon as I plugged in an iPhone to charge.

arthurb@aetna:~$ lsusb -t
/:  Bus 08.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 07.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 06.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/8p, 480M
    |__ Port 5: Dev 3, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
    |__ Port 5: Dev 3, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/4p, 480M

dmesg:
[ 1907.418073] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.418873] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.419849] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.420851] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.421873] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.421880] hub 5-1:1.0: Cannot enable port 2.  Maybe the USB cable is bad?
[ 1907.422847] hub 5-1:1.0: cannot disable port 2 (err = -71)
[ 1907.423848] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.424847] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.425864] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.426847] hub 5-1:1.0: cannot reset port 2 (err = -71)
[ 1907.427871] hub 5-1:1.0: cannot reset port 2 (err = -71)

(I can confirm that the USB cables is OK, i use it to sync the iPhone on another computer)

syslog shows other usb devices stopping:
Oct 22 11:59:23 aetna kernel: [ 1907.468066] hub 5-1:1.0: Cannot enable port 3.  Maybe the USB cable is bad?
Oct 22 11:59:23 aetna kernel: [ 1907.469060] hub 5-1:1.0: cannot disable port 3 (err = -71)
Oct 22 11:59:23 aetna kernel: [ 1907.470083] hub 5-1:1.0: cannot disable port 3 (err = -71)
Oct 22 11:59:24 aetna kernel: [ 1908.731548] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 11:59:27 aetna kernel: [ 1911.131666] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 11:59:30 aetna kernel: [ 1914.651551] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 11:59:32 aetna kernel: [ 1917.051358] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 11:59:33 aetna kernel: [ 1917.690338] hub 3-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
Oct 22 11:59:33 aetna kernel: [ 1917.690351] usb 3-1: USB disconnect, address 2
Oct 22 11:59:33 aetna bluetoothd[1923]: HCI dev 0 down
Oct 22 11:59:33 aetna bluetoothd[1923]: Adapter /org/bluez/1917/hci0 has been disabled
Oct 22 11:59:33 aetna bluetoothd[1923]: Stopping security manager 0
Oct 22 11:59:33 aetna kernel: [ 1917.690422] btusb_intr_complete: hci0 urb ffff880138479240 failed to resubmit (19)
Oct 22 11:59:33 aetna kernel: [ 1917.690441] btusb_bulk_complete: hci0 urb ffff880136c42780 failed to resubmit (19)
Oct 22 11:59:33 aetna kernel: [ 1917.691473] btusb_bulk_complete: hci0 urb ffff8801378d5540 failed to resubmit (19)
Oct 22 11:59:33 aetna kernel: [ 1917.691769] btusb_send_frame: hci0 urb ffff8800378a3cc0 submission failed

and I can certainly confirm the external keyboard and mouse stop. logs are slowly filling with
Oct 22 12:03:21 aetna kernel: [ 2145.190172] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 12:03:23 aetna kernel: [ 2147.870311] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 12:03:26 aetna kernel: [ 2150.280165] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 12:03:28 aetna kernel: [ 2152.960301] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 12:03:31 aetna kernel: [ 2155.360301] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 12:03:33 aetna kernel: [ 2158.041563] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 12:03:36 aetna kernel: [ 2160.440236] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 12:03:36 aetna kernel: [ 2160.881300] hub 2-0:1.0: unable to enumerate USB device on port 4
Oct 22 12:03:39 aetna kernel: [ 2163.351288] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 12:03:41 aetna kernel: [ 2165.781297] hub 2-0:1.0: connect-debounce failed, port 3 disabled
Oct 22 12:03:44 aetna kernel: [ 2168.460308] hub 2-0:1.0: connect-debounce failed, port 2 disabled
Oct 22 12:03:46 aetna kernel: [ 2170.860306] hub 2-0:1.0: connect-debounce failed, port 3 disabled
repeated.