I have an ASUS M5A78L-M LX V2 motherboard, the usb ports of which are all USB 2.0. I realised that my wireless USB card was working and connecting much faster connected to the front panel USB ports. Here is the syslog output when it is connected to the motherboard USB ports:

http://paste.ubuntu.com/1269611/

It did connect eventually...

And here it is connected to the front panel:

http://paste.ubuntu.com/1269619/

As you might have seen, the log shows that connected to the front panel, the usb is 2-x, while the back is 1-1.

lsusb while connected to front panel:

http://paste.ubuntu.com/1269622/

lsusb while connected to MB ports:

http://paste.ubuntu.com/1269622/

As you can see, lsusb thinks that 5 of my USB ports are USB 1.1. Even though I disable legacy USB in the BIOS.
When timed, the back panel took 18 seconds to detect the netwoork, while the front panel took, if not immediately, 1-2 secs to detect the network.

Sorry for the long post, all help is greatly appreciated.