Need help with downloading new programs, "stuck in Itunes"

[rabar51]

1) After attempting to run Lite Tweaks, it began the process but this window popped up:

<There was an error while  Removing unneeded packages!>

2) Everytime that I open the Menu->System->Install/Remove I get a window that says:

E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.