did I upgrade to squeeze properly?

[Michael Fothergill <michael.fothergill@googlemail.com>]

Dear Debianists,

I upgraded to Squeeze recently.  My sources file looks like this:

spc1-burn4-0-0-cust452:/etc/apt# more sources.list
# 
# deb cdrom:[Debian GNU/Linux testing _Etch_ - Official Beta amd64 DVD Binary-1 
20070317-22:49]/ etch contrib main

#deb cdrom:[Debian GNU/Linux testing _Etch_ - Official Beta amd64 DVD Binary-1 2
0070317-22:49]/ etch contrib main

deb http://ftp.uk.debian.org/debian/ squeeze main contrib non-free
deb http://ftp.uk.debian.org/debian/ testing main contrib non-free
#deb-src http://ftp.uk.debian.org/debian/ squeeze main contrib non free

#deb http://security.debian.org/ squeeze/updates main contrib
#deb-src http://security.debian.org/ squeeze/updates main contrib

#deb http://ftp.uk.debian.org/debian/ lenny main

#deb http://security.debian.org/ lenny/updates main contrib     
spc1-burn4-0-0-cust452:/etc/apt# 


Is it OK to have the deb http://ftp.uk.debian.org/debian/ squeeze main contrib non-free address and the deb http://ftp.uk.debian.org/debian/ testing main contrib non-free repository address (or whatever it is called) in their together or should only one of them be in there e.g. the testing one?

Do they work together in a complementary fashion or could they poison one another because the deb files in there could be a little different and it would screw things up?

Regards

Michael Fothergill