Latitude E6400 in docking stations slows down to a crawl

Over the last month my Latitude has continually slowed down while in docking mode.  I have to force close and then restart out of dock.  Once restarted I can then reboot and start in dock.  Have checked core temps and they seem okay.

Laptop works fine out of dock.  Also works fine with printers, mouse, keyboard, etc. connected direct to computer.

Have run virus and malware scans.  Nothing shows up.

Any suggestions would be greatly appreciated.