Hardware :: Mount Portable Hard Drive

I'm trying to mount a seagate portable hard drive. I can mount this device on my other machine except for this machine wherein every time I put the device, it was not being recognize. The led of the portable device just keeps on blinking. When I do fdisk -l, I don't see the device. When I do dmesg, I found the ff:

I used to mount this hard drive before and it was doing fine except last month wherein I cannot mount it anymore. I don't want to reboot and use LiveCD just to backup my files because other people are also using this machine (its a samba server). I tried to use other usb slot but still the same. I'm using CentOS 5.3 minimal installation. i tried to modprobe -r uhci_hcd and modprobe -r ehci_hcd and command again modprobe ehci_hcd and modprobe uhci_hcd but still the same.