Photoshop CS2 redraw garbage when moving around an image window on my G4 laptop

Question

Hi.I recently had to reinstall Photoshop CS2 onto my Mac Laptop 1.5 GHz PowerPC G4, running system 10.4.11, which required a new hard drive after the old one died. I am immediatly encountering a serious redraw/image repositioning problem in Photoshop that I have never seen before, and in Imageready as well. This does not happen in Macromedia Fireworks 8 however.
I am zoomed into an image. Using the hand tool, or the scroll bars or the arrows, as soon as I move an image little messed up line graphic glitches appear and stay in place for the remainder or working with an image, and ultimately covers the image completely after moving around within it a number of times. you can see examples of this in these screenshots I've uploaded:
http://pixeljam.com/temp/photoshopRedrawGarbage/moveGarbage04.gif
http://pixeljam.com/temp/photoshopRedrawGarbage/moveGarbage03.gif
http://pixeljam.com/temp/photoshopRedrawGarbage/moveGarbage02.gif
and the lines stay the same size and position even when zooming in. here's the same image w/ the same defects zoomed out and in:
http://pixeljam.com/temp/photoshopRedrawGarbage/moveGarbage01.gif
http://pixeljam.com/temp/photoshopRedrawGarbage/moveGarbage01_zoomed.gif
I've tried trashing & re-installing photoshop completely, tried running it before the updates needed from the original Photoshop application disk, and after. still the same problem.
This occurs only when using the laptop on its own. When I hook it up to my Apple Studio Cinema Display, it works fine. The problem does not occur on the Cinema Display OR the laptop screen! it's very odd. Basically, the laptop is now something I cannot actually use away from my desk until this is resolved.
Has anyone ever encountered this or possibly have any suggestions or advice? Thanks so much!
-Rich
And here are some more specs on my computer & hardware:
Hardware Overview:
Machine Name: PowerBook G4 12"
Machine Model: PowerBook6,8
CPU Type: PowerPC G4 (1.5)
Number Of CPUs: 1
CPU Speed: 1.5 GHz
L2 Cache (per CPU): 512 KB
Memory: 1.25 GB
Bus Speed: 167 MHz
Boot ROM Version: 4.9.0f0
Serial Number: 4H5456AZRJ7
Sudden Motion Sensor:
State: Enabled
Version: 1.0
GeForce FX Go5200:
Chipset Model: GeForce FX Go5200
Type: Display
Bus: AGP
VRAM (Total): 64 MB
Vendor: nVIDIA (0x10de)
Device ID: 0x0329
Revision ID: 0x00b1
ROM Revision: 2122
Displays:
Color LCD:
Display Type: LCD
Resolution: 1024 x 768
Depth: 16-bit Color
Built-In: Yes
Core Image: Supported
Mirror: Off
Online: Yes
Quartz Extreme: Supported
Cinema Display:
Display Type: LCD
Resolution: 1680 x 1050
Depth: 32-bit Color
Core Image: Supported
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Supported
DIMM0/BUILT-IN:
Size: 256 MB
Type: Built-in
Speed: Built-in
Status: OK
ATA Bus:
MATSHITADVD-R UJ-845E:
Capacity: 1.72 GB
Model: MATSHITADVD-R UJ-845E
Revision: DMP2
Serial Number:
Removable Media: Yes
Detachable Drive: No
BSD Name: disk5
Protocol: ATAPI
Unit Number: 0
Socket Type: Internal
OS9 Drivers: No
S.M.A.R.T. status: Not Supported

Answer 1

Hi. Thanks for your responses. There is definitely some incorrectness in the info I provided about the computer. for the Hard Drive, it's odd.. I copied and pasted that from my system profiler.. In actuality the Hard Drive is 74.53 GB. Not sure how that error occurred.
Also I looked again at the computer's memory. I forgot the second larger 1GB memory card when I was copying and pasting from the system profiler. Sorry about that. I was in a but of a rush to get the question out.
DIMM0/BUILT-IN:
Size: 256 MB
Type: Built-in
Speed: Built-in
Status: OK
DIMM1/J31:
Size: 1 GB
Type: DDR SDRAM
Speed: PC2700U-25330
Status: OK
Another thing I noticed about the problem I'm facing is that it leaves defects from mouse trails as well in the image window. None of the defects are lasting nor will they print. I close the file and they go away, if I zoom, they stay the same size. I'd agree, it sounds like a video card problem, but the reason I posted here is that only in photoshop and imageready do these problems occur. My guess, if it's the video card is that they are just programs that require more of the system. why my video card would be crapping out now, I have no idea. but I guess that's how it goes.
But why would it work fine when hooked up to the apple cinema display? even on the laptop screen itself the problem is not present. only when the laptop is on its own.
The computer has served me very well for almost 3 years without this problem, so that's why it's something that is not a normal problem that should be expected from this computer. I am grateful to have it & can't afford a new one.. this one is still sitting on my credit card balance. Thankfully I am under the applecare protection plan and will bring it in to the local Mac shop on monday and demonstrate the issue to them.
Thanks for your replies.