You're going across releases, so there may be specific builds for that release and the app will need to be downloaded again. You're also trying to migrate the apps to a development release, so some apps may not be available yet, either waiting for QA and approval, or waiting for patches to make them compatible.
There are other ways of doing this, that might ensure that you get the correct versions and that the dependencies are met correctly. I have this one in my notes:
To make a file with all installed applications on the system:
On working system:
dpgk --get-selections | grep -v deinstall > ubuntu-files
To then install the packages listed in this file:
### Make sure the system is fully updated
sudo apt-get update && sudo apt-get upgrade
### Install the dselect tool (probably depracated)
sudo apt-get install dselect
### Give the package list to dpkg so it knows what to install
sudo dpkg --set-selections < ubuntu-files
### Use dselect to initiate installation (option 'I' will do it)
NB: There might be a better way to do this, for example calling dpkg directly
instead of installing and using dselect.
NB: Although all packages are listed only those that do not exist on the system
will be installed by dpkg
NB: cross version installation not really recommended - may install obsoleted
packages (Open Office) and unwanted themes and dependancies (eg as in upgrade
from 10.04 to 11.04 with Unity
Again, as noted, cross version installation may not be ideal, but at least this way the packages will be installed fully from the correct repository. You can still use the .deb files and restore them to /var/cache/apt/archives so that they don't have to be downloaded again, however if a newer release is required or is available it will still have to be downloaded obviously.