Scanner Questions

Hello everyone, I'm looking for some help understanding a situation I have going on with my 600 MHz iBook running the latest update to OS X. My question is in regard to the use of my new HP scanjet 3570c that uses a normal USB connection. When I plugged it in I noticed that everything slowed down. I, being the suspicious type, opened up my CPU Monitor and sure enough it was mostly red and using up practically all of this little G3's resources. When I unplugged the USB cable from the scanner (I wasn't actually using it at the time) the CPU Monitor went way down to normal levels showing almost all black with a speck of red and a bit of green. So my question is this. Why would the scanner be sucking up so much of my iBook's resources? Is there a fix for this? I already have the latest drivers from HP. So I want to know if you all have experienced similar issues and if so, possible fixes. Thanks for all your time.