I am unable to get any usb drives to mount unless I reboot.  All the usb drive devices I have tried work properly on other computers running Windows.  I have tried all the different USB ports on the computer.  Once I reboot the device is mounted and works flawlessly.  If I eject it, disconnect it, then reconnect it, it does not mount, until I reboot again.

I have tried the following usb drive devices:

• Sony 2GB usb flash drive
• Memorex 512MB usb flash drive
• Olympus FE-140 digital camera in usb pc-sync mode
• Sony DSC-H1 digital camera in usb pc-sync mode
• Samsung HD flash camcorder in usb pc-sync mode

If I run the USB Prober.app that comes with XCode, the connected device is listed, but running this application does not make it magically mount as suggested by some tech articles.

I have tried the IOUSBFamily.kext v308 posted here http://forum.insanelymac.com/index.php?showtopic=117029

This issue also occured with Uphuck 10.4.8.

Any suggestions?

I have the same problem. I am running iDeneb 10.5.5 on an Abit IP35 XE Pro motherboard, have been doing so with ALMOST no issue for weeks. Only major teething issue which won't go away is that of USB storage not detecting. The particular USB devices I use are namely a 250GB Lacie hard disk and a Kingston DataTraveller 8GB flash drive and an el cheapo 2gb flash drive from Tescos . This issue occured with both drives originally however after disabling USB storage legacy support in the BIOS the Lacie seems to be less tempermental. This issue still stands with both flash drives. They will work fine after a reboot and will even allow me to eject remove and reconnect with no issue. I also tried the modded USBFamily kexts with no joy. Also around 1 in every 10 boots I have to disconnect mouse or keyboard and reconnect to make it detect - the least of my problems but thought I'd mention it all the same. Let me know if you get anywhere with it and I shall do likewise for you. I bet there's a way round it... I'll keep fiddling.

http://forum.insanelymac.com/index.php?showtopic=95789 worked for me. All usb drives mount and unmount without the reboot.

Thanks for that 600dollar I will try that. I have got around the issue for the time being with a short script run at startup:

#!/bin/sh
echo "mypassword" | sudo -S rm -rf /System/Library/Extensions/Caches/

I think this was posted somewhere on the Insanely Mac forums, however don't have the time or energy to try and work out where. This seems to circumvent this issue. However when I have more time available I will try this solution.

try this
http://forum.insanelymac.com/index.php?showtopic=129932