I'm getting this message ......

The following packages are in a mess due to serious problems during
installation. They must be reinstalled for them (and any packages
that depend on them) to function properly:
sun-java6-bin

The following packages have been unpacked but not yet configured.
They must be configured using dpkg --configure or the configure
menu option in dselect for them to work:
java-common Base of all Java packages
odbcinst1debian1 Support library and helper program for accessing odbc ini
unixodbc ODBC tools libraries
gcc-3.3-base The GNU Compiler Collection (base package)
libstdc++5 The GNU Standard C++ Library v3

And here is the Java version

stefan@stefan-laptop:~$ sudo apt-get install sun-java6-bin sun-java6-jre sun-java6-plugin
E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
stefan@stefan-laptop:~$ java -version
java version "1.5.0"
gij (GNU libgcj) version 4.2.1 (Ubuntu 4.2.1-5ubuntu5)

The part in bold is the main problem because I am unable to check updates because the same error pops up. When I tried to follow the one hint to go to system->administration->synaptic package manager I get this same errorE: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem. and E:_cache->open ()failed, please report.

If anyone could help me that would be great !

Run the dpkg --configure -a command as root, and it should fix any errors.

How to run it manually:
(in a terminal)
After that, updating should be possible.

I tried and it still doesn't work. At one point it was showing signs that ok it's working until I try to install new updates and it does the same thing :S

Could you please post some output (and wrap it in the [ code ] [ /code ] tags), along with your /etc/apt/sources.list file?

Also, which command are you using to install updates? I've always used:

sorry for troubles, I guess after couple of times that I restarted my computer and tried it again, somehow it started working again, so thanks to all who helped !