Savvas, that's not the (meta-)package that doesn't exist, but the package that refers to the one which doesn't exist:
$ apt-cache policy linux-backports-modules-compat-wireless-2.6.36-generic N: Unable to locate package linux-backports-modules-compat-wireless-2.6.36-generic N: Couldn't find any package by regex 'linux-backports-modules-compat-wireless-2.6.36-generic'
Savvas, that's not the (meta-)package that doesn't exist, but the package that refers to the one which doesn't exist:
$ apt-cache policy linux-backports -modules- compat- wireless- 2.6.36- generic -modules- compat- wireless- 2.6.36- generic backports- modules- compat- wireless- 2.6.36- generic'
N: Unable to locate package linux-backports
N: Couldn't find any package by regex 'linux-