concurrency access to workflow items - error message

I know that, although it could be difficult to capture the requests made from browsers and distinguish the concurrency issues associated with the work-flow action item updated, and not limiting an user to not be able to view all work-flow actions available to her at the time of editing (not knowing somebody had already triggered that request), I think we could do better then just saying "Error Action 161 is invalid"

Perhaps something like "That action that you trying to execute is not available due to concurrent access" (or something like that)

Your thoughts? Discussed this with Chris M

Thanks,
Ib