I'm new to GPO so please excuse the ignorance! I'm using the Vst plug-in of GPO and I have 7 instances of the player running. Some of these players have two or 3 instrument slots open (I've done this so I have an instance of the player for woods, 1 for horns etc and so on) The thing is, my processor load (3.2G P4 HT) is up around 30% with nothing playing! This seems a little excessive to me, because my machine is well above the recommended spec for the software and if this is normal, then the recommended spec wouldn't even be able to run 2 instances, let alone a full orchestra's worth!
Please let me know if this is normal, or just me being and idiot!
You didn't mention what you are running GPO/VST in. If it's Cubase SX (as I am) I often see a CPU load (with that little meter thingy) and I've come to associate it with memory fragmentation that is usually solved by  saving the Cubase project (if anything has changed),  shutting down Cubase SX and  restarting Cubase SX and the project. A total shot in the dark (and no ready explanation about "why" this "works" or makes a difference) but computer stuff is sometimes reduced to mythology such as this.
You probably have loaded in some wet instruments or are using Ambience plugin which will use about 20% CPU. On a P4 2.8 GHz machine my load is about 10% with 6-8 instances of Kontakt and the Kontakt Player loaded with about 50 instruments. This is as a VST in Sonar 3.1.1 and using the Lexicon Pantheon reverb.