Are both base stations using the same channel? (configured via the Bs utility)
Some channels may be more or less effective in certain areas (depends on environment, portable phone usage etc). At home, some channels give me more drop outs than others.
Do you have a lot of metal in the walls at work? (Is it a corporate center, converted home etc)
Do you have the airport set to connect to a specific network or to the one with the best signal? (in Network preferences)