the buttom right of screen messages :(

in Preferences -> Messages, i have selected “minimize the message windows to the taskbar” and “show messages at buttom right of screen”. but if i’m running a full screen application it doesn’t appear. even if i select “keep yahoo messenger on top of other applications” it still doesn’t work. i like the messenger 7.5 and I don’t want to go back to 7. in 8, this alsow doesn’t work. if anybody konws how to resolve this, or if it can be done, pls tell me!