I don't know if it's a bug or not.

I'm running U-8.10 x64 on a HP Pavilion AMD Athlon X2 Vista x64 machine and
U-8.10 x32 on a P-4 powered ECS motherboard XP Pro macine, minus the XP Pro.

In both cases Ubuntu works flawlessly.

Could you tell us more about your cameras and computers?

Camera is Powershot A510, Mounted and worked perfectly in Ubuntu 8.04

My puter, now updated to 8.10 Ubuntu

Motherboard Mach Speed MSNV-939
AMD Athlon 64 X2 3800+
3 Ultra 1024MB PC3200 DDR 400MHz Memory

I'm guessing that the camera isn't mounting now?

I was troubled by some very difficult to understand USB port issues on my P4
computer. Ubuntu, any version, would not recognize the USB ports, it drove me
nuts for a while. To make things worse Ubuntu would occasionally recognize the
USB ports just once and then refuse to work again. For some reason I could
wiggle the USB memstick, in this case, and wallah! it would mount, leading me to
believe that it might be a defective solder joint in the USB connector area of
the motherboard.

To further complicate things I tried Mandriva One and it recognized my USB ports
everytime, but I had other problems with Mandriva that were unrelated to the USB
port problem, so I went back to U-8.10 again to have another look at the USB
problem.

With a fresh install of 8.10, I set and reset the Bios USB options on my ECS
motherboard, including the Legacy option, without having any effect on the
intermittent USB issue. At some point in this exercise I noticed that my Bios
had an option, F9 in my case, that said it would reset the Bios to its original
defaults.

Once I reset the Bios with the F9 option everything worked perfectly,
no issues at all.

I don't know if restting your Bios will fix your issue but after restting mine
I've been able to use my USB ports for all of my toys without issue.