G5 problems.

I have a 1.8 gig single processor G5 running 10.3.7. It has 256 megs RAM with another 1 gig on the way (if Mac Mall ever get their finger out of their rear). I have MS Office 04, Pshop 7, Illustrator CS installed. I have a Brother HL-1440 laser printer, Canon PIXMA 6000D inkjet and a Canoscan 8400 all connected along with the required drivers, I have a powered Belkin USB 2.0 TetraHub connected. The printers and the scanner all work fine with my G3 iBook.

Problems
Freezes
Doesn't seem to like iTunes (4.7.1)
Won't wake up after sleeping (addressed elsewhere in this forum)
When asked to print a single page to the Brother, kept on trying to access the Canon and then eventually took the instruction to print to the Brother, printed 11 pages - the one I wanted, plus 10 pages with 1 or 2 lines of symbols across the top of each. Eventually I just had to power off the printer to get the printing to stop.

I have put some (maybe most) of the freezes down to insufficient memory. The rest seem to be related to some iTunes conflict (again possibly a memory problem), At least, I get a lot more freezes with iTunes running than without. Am I right?

I've never had issues like this with any previous Mac, what the hell is going on? Things are bad enough for me to consider a call to Apple support.