USB dongle not recognized


I have a USB dongle that I keep inserted into one of the two USB ports on my MacBook Pro. It would always work just fine until after I upgraded to OS X 10.9. Now I need to remove the dongle and re-insert it before it is recognized. I know this is due to the recent upgrade of the OS I just don't know or understand why this is happening. Any suggestions on correcting this problem would be appreciated. I know I can get it recognized by removing it and re-inserting it but that is a pain.


What exactly is that dongle?
That is, what is its purpose?
Is it a hardware security key of some kind (to allow use of some software?) - or something else?

If it is just storage (USB flash drive), I would suggest backing up the files somewhere else, then erasing, and restoring the files. That may result in a flash drive mounting more reliably. If that doesn't help, then you may simply have a flash drive that needs to be replaced.
It is is some kind of hardware key, either as security, or other external hardware device, then there may be some updated drivers, or other update available from the supplier. Have you checked at the manufacturer's (or supplier's) site for possible info about that?
And... if it is a USB Hub and it has its own power source, check to make sure you have the plug set in the outlet securely.
If you are using a power strip or surge protector, check to make sure it is working properly. I have had power surgers fail.