USB ports working intermittently on dock is a fairly common issue.
When I dock my T410, about 10% of the time the mouse does not get power, and about 30% of the time the keyboard does not get power. Undocking/redocking, or even just wiggling the laptop around the connector a bit solves the issue after 1-3 attempts.
Current: X220 4291-4BG, T410 2537-R46, T60 1952-F76, T60 2007-QPG, T42 2373-F7G
Collectibles: T430s (IPS FHD + Classic Keyboard), X32 (IPS Screen)
Retired: X61 7673-V2V, A31p w/ Ultrabay Numpad
Past: Z61t 9440-A23, T60 2623-D3U, X32 2884-M5U