USB Kernel 2.6 (Not the usual prob.)

[Adam Cooper <adam cooper port ac uk>]

Hi guys. 
I've got a pain in the ass problem. I've googled it, searched the
archives for it, all sorts.

I took yesterday to install arjanv 2.6.4 kernel on my Dell 5100 Laptop.
I've installed a vanilla Kernel 2.6.4 on my desktop so I knew faguely
that things should be ok.

I followed the guide:
http://www.freax.be/wiki/index.php/Fedora%20core%201%20with%20kernel%202.6-test

Which all went smoothly. However I cannot get USB to function. The guide
mentions adding:

"alias usb-controller ehci-hcd
 alias usb-controller1 uhci-hcd"

to modprobe.conf (Yes I've got USB2). Yet it does not work on a reboot.
If I manually type:

"sudo /sbin/modprobe uhci-hcd"

then USB springs to life. More importantly my USB mouse works. 

Whats with that? Why does the /sbin/modprobe work but the modprobe.conf
not?

Cheers for any help.
Adam