Friend connected but "disconnected" on friendlist.

Well, i play with two friends Cross Fire. I added them as friends and at the start it worked good, i cought see them connected at friendlist and know at where server and channel were they connected.

But these days, sometimes while my friends are connected and playing, they appear as "disconnected" at the friendlist, but they're playing the game. Also, if I try to whisper them (/w playername) it sends me the error: Unable to whisper. But my friends are connected!!! What should I do? It's a game bug? Any way to fix it?

Thank you!