Hi,
I'm also a newbie using Fedora Core 3 (on a Dell 600m). I don't know if this will fix the IRQ problem, but this is what I did to get a 64MB stick to work:
1. Open up a terminal and make yourself root:
[user@localhost ~]$ su root
Password: type-in-your-password
[root@localhost user]#
2. create a folder into which you can place (mount) the memory stick information. I called the folder "usbmem" and placed it into the "media" folder:
[root@localhost user]# mkdir /media/usbmem
3. edit the File System TABle (in the file /etc/fstab), which is where the system looks to know what to do with hard drives, CDs, memory sticks, etc.
[root@localhost user]# gedit /etc/fstab
This opens up the fstab file in the Gnome Editor (ignore all the messages about permissions and stuff; something about SELinux is going on). Using the Gnome Editor, add this line to your fstab file:
/dev/sda1 /media/usbmem vfat noauto,users,rw,umask=0 0 0
and end it with a carriage return, then save. The "/dev/sda1" is what my system calls a new USB memory drive, and the line above says that it will be in vfat format, that the contents should be placed into /media/usbmem, and gives various permission information.
Now exit out of being root and close the terminal.
4. Instruct the system to automatically mount drives that are inserted or hotplugged. In Gnome, you go to:
Applications > Preferences > Removable Storage
Make sure that "Mount removable drives when hot-plugged" and "Mount removable media when inserted" are selected. Close. I don't know how to do this in KDE, but I'm sure there's something similar.
That's all I did, and now when I stick in a USB memory stick, it takes a few seconds, and then a USB memory icon appears on the desktop. Hope that helps.