I dont know where you check the supported cpu list but I see Q95505S is support see here

Code:
ntel	Core™ 2 Quad Q9650	3.00GHz	12MB	Yorkfield	45nm	E0	95W	1333	F4
Intel	Core™ 2 Quad Q9550	2.83GHz	12MB	Yorkfield	45nm	E0	95W	1333	F4
Intel	Core™ 2 Quad Q9550s	2.83GHz	12MB	Yorkfield	45nm	E0	65W	1333	F7
Intel	Core™ 2 Quad Q9550	2.83GHz	12MB	Yorkfield	45nm	C1	95W	1333	F4
Intel	Core™ 2 Quad Q9505s	2.83GHz	6MB	Yorkfield	45nm	R0	65W	1333	F10
Intel	Core™ 2 Quad Q9505	2.83GHz	6MB	Yorkfield	45nm	R0	95W	1333	F10
Intel	Core™ 2 Quad Q9500	2.83GHz	6MB	Yorkfield	45nm	R0	95W	1333	F10
You need bios F7 to support the cpu