Instant Message Box is behind Chat sub menu

Need your guys help! when member send instant message to member IM box (flash) will appear on the top left of the browser showing that someone wants to talk to you.

The problem is when it comes to resolution 1024 X 768 that box will be under hidden menu which happens to stay when you click "Chat"

I tried to change z-index in general.css for .hiddenMenu class but it still doesn't work. What should I do?

Are there anyway to either

1. Make hidden menu not appears when it's a active page

2. set transparency in flash

3. Change z-index for hidden menu?

Thanks in advance guys