Presentation director refresh rate?

[qazthinkzaq]

Hi,
I have t60p With Ati v5250. When in presentation director i change the display scheme that message apears
"The following settings you have selested cannot be applied properly. .... External monitor or projector Refresh rate"
How to set external monitor in 85hz? In catalist i have onely 60hz.
best regards
p.s. external monitor is Sony g200 with installed driver. Windows XP Pro. Ati catalist control center v.1.2.2447.13670.
presentation director v.2.54

[qazthinkzaq]

OK its may be the stupid question but
How to set 85hz to external monitor ?
Any suggestion will be appreciated.