you have installed the correct driver for the card? Don't take the Windows device manager's word for the fact that something is working OK - it will do that as long as there's no resource conflict and as long as it detects a driver is installed. The driver may be a generic one, and not necessarily suited to your card.
I'm a bit puzzled that the system tray icon says the card is "lost" - that's an unusual message to say the least. What make is the card?