First of all, make sure your fsb is set to 133MHz rather than 100. But that will only increase your speed to 1133MHz.

What's your motherboard? Does it support the XP2200+? It sounds as if it is not recognising your chip correctly and is only assigning a multiplier of 8.5 rather than the correct 13.5 multiplier, particularly as the info from the mobo section of AIDA32 says it is a Duron processor.

Edit: It may be that you need a bios update to support that chip - check with your board manufacturer.