Please can anyone help?

I have just purchased the iomega zip 100 and i'm having a problem, when i try to do a back up. The problem is that when i start a backup windows locks up, i have a canon bjc 3000 connected via usb and when i remove this, back up works ok without locking up. Can anyone help as unplugging my printer cable everytime i do a backup is time consuming as i have to shut computer down to do this. Your Advice and opinions are much appreciated.

stu