unable to remove conflicting program "flashplugin installer"

[Manish Kumar]

I downloaded "flash player-10" from official site and when I am trying to install it in Ubuntu 10.10- Ubuntu Software Center says "Conflicts with the installed package 'flashplugin-installer' ". So what I tried to do is to remove it from installed software in Ubuntu Software Center named"Adobe flash Plugin-Installer for the Adobe flash plugin for Mozilla".
But when I am clicking on Remove button a window opens up saying "An Unhandlable error occurred"
Screenshot is attached.

Details show:
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/aptdaemon/worker.py", line 768, in simulate
    return self._simulate_helper(trans, status_path)
  File "/usr/lib/python2.6/dist-packages/aptdaemon/worker.py", line 936, in _simulate_helper
    return depends, status, self._cache.required_download, \
  File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 218, in required_download
    pm.get_archives(fetcher, self._list, self._records)
SystemError: E:I wasn't able to locate file for the ttf-mscorefonts-installer package. This might mean you need to manually fix this package.