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

Thank you for taking the time to report this bug and helping to make Ubuntu better. Unfortunately we can't fix it, because your description didn't include enough information. Furthermore
1. Please try to run 'sudo dpkg --configure -a' in a terminal window before reporting errors.
2. Where is this Limewire P2P. I wonder if it is an official / supported package.

On the other hand if you think this is still a valid bug, please consider the following advice: You may find it helpful to read "How to report bugs effectively" [WWW] http://www.chiark.greenend.org.uk/~sgtatham/bugs.html. We'd be grateful if you would then provide a more complete description of the problem.

We have instructions on debugging some types of problems. [WWW] http://wiki.ubuntu.com/DebuggingProcedures

At a minimum, we need:
1. the specific steps or actions you took that caused you to encounter the problem,
2. the behavior you expected, and
3. the behavior you actually encountered (in as much detail as possible).
Thanks!

what shall I do to solve this problem

This error occured when tried to upgrade to Ubuntu 8.04

Thank you for taking the time to report this issue and helping to make Ubuntu better. Examining the information you have given us, this does not appear to be a bug report so we are closing it and converting it to a question in the support tracker. We appreciate the difficulties you are facing, but it would make more sense to raise problems you are having in the support tracker at https://answers.launchpad.net/ubuntu if you are uncertain if they are bugs. For help on reporting bugs, see https://help.ubuntu.com/community/ReportingBugs.