Slow iDVD3

Hi, can anybody solve this problem?
I am running a dual 1GHz G4 mac 768MB ram with OSX 10.2.6 with superdrive.
After installing ilife iDVD3 & 3.01 upgrade iDVD3 run so slow it is unusable. It takes approx 2 minutes to load and composing a DVD takes longer than burning one. You are constantly faced with the spinning death wheel after every action (mega frustrating), imovie3 also takes a mile to load but runs fine. The old iDVD runs & loads with a flash in OS9 but alas is not up to date.
I have repaired everything using the utility disk as mentioned on most sites and have even reinstalled the system and upgraded to 10.2.6.
After reverting to iDVD 2 which runs at least 10 times faster, surely apple must realise this is a step backwards?
Can anybody help as iDVD3 seems to be excellent in its make up and look.
PS I have burnt one DVD (PAL) with video and slides which looks superb but getting there was a nightmare!
There must be someone of the knowledge to sus this, and thumbs down to apple for not caring.
Regards Gus, Long standing apple user How long!!!

Thanks for that, it has helped me loads,
Nice plants though!

768 MB ram and piont taken!
Query, reverting to iDVD2 works and runs 10 times faster (at least) surely it can't be ram related?
I also have another G4 and have upgraded to the same software spec, it is just as slow running iDVD3 (to prove a point).
I'm bafled!😕