ok i never used this program but i gonna give it a try
but the thing i am wondering about is
eventually you need to compress the video so it fits on the dvd-r from 4.7GB

so i removed all the foreign languages except english
then i need to use the compression level untill it fits

BUT

the compression is this something noticable
i mean can you see anything during the movie which points to the compression
like i want to make a backup from my minority report dvd
which is 7 GB
i need to use compression level 10
would this be something u can see eventually when watching the movie ?

At level 10, yes. Very much so. I'd have to suggest movie only for that particular title. Been ther, done that. Was not happy with full disc quality at all.

so which would be the highest compression level that should not be crossed
to keep the quality decent

imho,
very subjective, beauty in the eye of-----etc.
just done level 10 compression on a dvd, plays great on my sony 44 rp tv no pixelating or artfacts of any kind, better than vhs by a long way.
pioneer a04, record now max, 2x verbs @2x burning.
if you want back up perfection buy 2 originals.

ok thx for the info guys gonna keep the compression as low as possible
offcourse compression or not it stays a copy
and nothing beats the original imo

btw does the burning tool make any difference like nero or primodvd or any other which is the best for this kinda thing anyway

I found that once it gets to about a compression level of 4 you start noticing the difference between it and the original DVD. Level 3 and above you really can't notice a thing. I have pretty high standards for quality though. Keep in mind that you do have the reauthoring feature (although you will lose the startup menu) and it will get rid of all of the extra junk except the movie itself (and it's audio tracks). This can save you a few levels of compression.

this gives an idea of whats happening (from shrink forum) :-
http://members.optusnet.com.au/~virho/
all dvd films are not equal, some are poor quality on original dvd, there for will accept more or less compression as the case may be.(extras can also make a dvd worth backing up{lol} giving it more replay value).
also to bear in mind is the viewing and play back av equipment quality, and the quality of media used (many artfacts etc. are associated with poor media).
as for burning software, i`ve used nero, primo, and a few more with good results, but i`ve never had a bad burn with stomp rnm, ever!!!!!!!

Yep, I find with anything above level 4 the results are usually much better using IC7.