Never seen that particular problem before! Nevertheless, it should be possible to fix, provided the problem isn't in the repository (which is of course a possibility).

First, try refreshing the repository list in application manager. This should normally correct the problem. Alternatively, you may do an 'apt-get update' at the command line to the same effect (but try through the application manager first, I'm not certain exactly what the AP does differently from apt).
After that, do an 'apt-get clean' at the command line, to be sure the files are re-downloaded at the next step.
Then, try installing again.

If the update fixed the problem then the installation should work by either method. If it didn't, then either the repository is broken, or the downloaded files somehow get corrupted when you download. Unless the flash storage is broken (unlikely) or the filesystem runs full while you download then it must be a repository problem. But hopefully that refresh fixed it.

EDIT: A couple of minor typos.