USB bus fails to see devices

[Haines Brown <brownh@hartford-hwp.com>]

I've been able to use all my USB devices (camera, scanner, printer,
bub, etc.), but at one point that I can't associate with any event, two
devices (camera and scanner) are no longer seen by the USB bus.

	$ uname -a
	Linux teufel 2.6.18-4-686 #1 SMP Wed May 9 23:03:12 UTC 2007 i686 
		GNU/Linux

	$ apt-show-versions udev
	udev/etch uptodate 0.105-4

The printer and scanner are connected to the root hub; the printer is
seen, but not the scanner. A camera, usb-key and usb external hard
disk are connected to an external hub; the latter are seen, but not
the camera. I disconnected irrelevant devices to eliminate any usb bus
power issues. and so it seems the bus and cables are OK.

However, the bus does not see my Canon camera and Epson scanner, while
it does see a Western Digital USB external HD, a Lexar USB-key, a
Genesys USB hub, and a Lexmark printer:

	$ lsusb
	Bus 002 Device 011: ID 1058:0701 Western Digital Technologies, Inc. 
	Bus 002 Device 009: ID 05dc:a400 Lexar Media, Inc. 
	Bus 002 Device 002: ID 05e3:0605 Genesys Logic, Inc. USB 2.0 
		Hub [ednet]
	Bus 002 Device 001: ID 0000:0000  
	Bus 001 Device 004: ID 043d:0052 Lexmark International, Inc. 
	Bus 001 Device 001: ID 0000:0000    

Likewise, in /var/log/syslog, when the printer or camera is replugged,
there is no report of it there at all.

The module list looks OK to me.

	$ lsmod | grep 'usb\|hci'
	usb_storage            71840  0 
	usblp                  12768  0 
	scsi_mod              124168  6 usb_storage,sbp2,sd_mod,libata,
					aic79xx,scsi_transport_spi
	ehci_hcd               28136  0 
	ohci1394               30800  0 
	ieee1394               86904  3 sbp2,eth1394,ohci1394
	ohci_hcd               18276  0 
	ide_core              110504  4 usb_storage,ide_cd,amd74xx,generic
	usbcore               112644  5 usb_storage,usblp,ehci_hcd,ohci_hcd

When I was runing Woody, stock kernel 2.4, I had something like:

	$ more /proc/bus/usb/drivers
		usbdevfs
		hub
	0- 15:  usblp

but with Etch, stock kernel 2.6 I have no such directory. Not sure
why. 

I'm having trouble understanding 
        
        $ dmesg | grep -i usb

for it looks like my printer and USB mass storage devices aer loaded
multiple times.

Should I have seen a /proc/bus/usb/drivers directory with some drivers
in it? Given the above, where is it likely the problem lies?
 

-- 
 
       Haines Brown, KB1GRM