I am using a mythtv build that is 1 1/2 to 2 years old so this might be the problem, but when i try to do a apt-get update it says Failed to fetch http://...... 404 file not found and it also brings this msg up
E: Dynamic MMap ran out of room
E: Error occured while processing qbrew (NewVersion1)
E: Problem with merdgelist /var/lib/apt/lists/ftp.de.debian.org_debian_dists_unstalbe_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened

even though it said it could not fech i tried to do apt-get install xine and apt-get install linneighborhood
and i got the same error messages.

Should i download the new mythtv version, or is there a way i can still download linneighborhood and xine on this old version?

With a system that old you're quite likely to break it beyond repair if you try to update using apt-get.

Compiling form source or upgrading to a more recent version are probably your best bets.

Check the sources.list located at:
/etc/apt/sources.list

I have these lines in there and was able to get linneighborhood:
deb http://ftp.us.debian.org/debian stable main contrib non-free
deb http://http.us.debian.org/debian stable main contrib non-free
deb http://non-us.debian.org/debian-non-US stable/non-US main contrib non-free
deb http://security.debian.org stable/updates main contrib non-free

Xine was installed, if I remember correctly, with R5C7.