"...Following packages have unmet dependencies"

[Noes]

I'm quite new to Ubuntu (switched from win7 about 2 weeks ago)

I'm using Ubuntu 11.04 64-bit and using the Ubuntu classic (GNOME) GUI

When running update manager I get the following error:

"Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

Please report this bug against the 'update-manager' package and include the following error message:
'E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.' "



When I try run sudo apt-get dist-upgrade via the terminal it says:

"Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Failed
The following packages have unmet dependencies:
libaccess-bridge-java : Depends: default-jre but it is not going to be installed or
openjdk-6-jre but it is not going to be installed or
sun-java6-jre but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages."


I don't have a clue what to do from there.

[Shazaam]

When I try run sudo apt-get dist-upgrade via the terminal it says

Are you trying to UPGRADE to Oneric?

[Noes]

I wasn't actually trying to upgrade. as far as I know 11.10 only releases on the 13th.
I ran the dist-upgrade just to see what would cause the problem.
Do I have to get rid of those packages? Are they important? would not having them cause any problems?
And If I do have to get rid of them, I don't actually know how but I'm sure I can find that with a little googling.

I'm not sure if it is relative but when running "sudo apt-get update" it updates for a while then I get the following message:
" W: GPG error: http://ftp.de.debian.org lenny Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA"