guest system Ubuntu does not recognize attached USB device

[hod]

My computer is a little old and has no USB 3.0. I use a PCI-e card which provides seven USB 3.0 ports. USB 3.0 is faster than USB 2.0.

[socratis]

The problem is not that you have a PCI card, the problem is that you forgot to mention it for 8 posts! And the fact that the card is problematic. That is NOT how you explain the problem to people that you're looking for help and are NOT sitting in front of your computer, or know your exact setup.

[hod]

I didn't know that PCI-e USB cards cause problems and you didn't ask me about the hardware, did you? The VIA USB card works very well with Windows 7 on the host computer. Do all PCI-e USB cards cause problems ? If so, why?

[asim2@slb.com]

I hit this very same issue, I tried to enable USB3 in my RedHat guest, but it would no longer boot when I did, so I disabled it again. I then attached a USB hub and plugged the very same USB stick in to it and it worked first time and every time since, so I tried again without the hub and confirmed cannot use USB sandisk drives unless I do so through a USB hub. Lexur I can sometimes (older ones seem better), Kingston I have only one and it works without a hub.

This is obviously a major bug in VBox and should be addressed.

[socratis]

I then attached a USB hub and plugged the very same USB stick in to it and it worked first time and every time since

Is the USB a USB 2 perhaps?

This is obviously a major bug in VBox and should be addressed.

Hold on to your horses there. You have not found a bug yet, what you have found is a yet-to-be-explained peculiar behavior in your specific setup. Far from proving a bug and a major one in particular...