Arizona Joe, What you should do is reboot the server to the raid controller (Ctrl-R, Ctrl-C, or Ctrl-M depending on the controller)  From there you need to verify the status of the drive first. If it is failed you can remove and replace if you like, or you can start a rebuild and see if the drive will rebuild to the array.  If the drive is in a foreign configuration then reseating the drive won't actually resolve the issue, you would need to clear the foreign from the controller before it would work. So the drive status is key. Let me know what you find out.
I running Xen on a 2950 with a RAID10.  One of the drives has a flashing yellow light and I assume needs to be replaced.  Everything I read says I should use Open Manage to take the drive off line.  Not possible since I can't run open manage in my Xen environment. Since the drives are hot swappable can I just pull the drive and replace it with a new one?  
Flashing yellow light delemma