Kernal panic

OK. I've now thinking I should just go buy a new i-Mac.
After installing Leopard on on G4 that already had been updated to Tiger with no problems things started to creak and eventually the Kernal panic story came. After a lot of messing around I eventually decided to start from scratch and erased the drive. Seemed like I had bad RAN (the internal DIMM) so I replaced this. After replacing the RAM I ran the complete suite of advanced tests from Tech Toll Pro and all passed with flying colors. Then strarted installing programs. I life 08. All going well until I tried Mail and it kept dying and needing restart. Thought it might be a bad install of mail so went on to I-photo and while importing photos from a CD the dreaded window of death (you must restart your computer) came. I read this is a new form of Kernal panic but cannot get the text to give you further details.
Cannot strt in DSAFE mode but Verbose works. Text comes up then it disappears and the normal desktop screen wipes it out.
Something is wrong somewhere, it's probably not terminal but unless you guys have ideas then my only other option is to pay Apple to take a peek. I'm wondering if it's worth the money or I should just stump up the $1500 for a new beauty?
Let me know what ideas you have.
My firmware is 4.5.9f1
Thanks

What specific mac is it, without that info we cant find out if there are any special issues with your model

have you run the 10.5.1 update?

Power Mac6.1, Flat panel 17 inch, 1
After loading the Tiger disc 10.4 I ran software update and but it quit before I could run it. Still 10.4 as far as I can see.
The disc permissions keep getting messed up. /libraryWidget and others (eg /usr/lib/php/build/scan/_makefile-in.awk)....I can repair but they keep coming back.
Reparing disc comes up consistently with Thim32segentData amongst others.
Try the FCSK story and it says disc cannot be repaired, but via disc utility I can repair but then later the disc permissions are back to hammered.
Thanks

I would do a complete reinstall from scratch (back-up first)

OK
I'm going to go step by step
I have erased the disc again (is it normal that 2 files are left even after erase?)
Installed Tiger. and am running the update to 10.4.11
After that I'll check if mail works and play with it a while. If all OK I'll start installing programs 1 by 1. Will get back on progress.
Thanks

OK

All was well until I installed the updates
I-Tunes
Java 1.3.1 and 1.4.2
Security 2007-009

Immediately after install I ran the disc permissions

/Applications//Tunes.app/contents/frameworks
Internetutilitiesbundle/contents/MacOS/internetutilities

Should be

-rw-rw-r
are -rwxrwxr-x

and

/Library/appsupport/macromedia/shockwave10/shockwave10preferences
should ve
-rwxrrwt-x
are
-rw-rw-r--

I can repair but I'm sure at some point more problems will emerge

What is going on here?

Thanks