Comment 1 for bug 1026858

This happens typically if your package index files are not up to date. I have the feeling that flashplugin-installer is particular sensitive to this issue, maybe because the code is dowloaded from a different site or just because it used to be updated more often than many other packages.

Can you reproduce this after running "sudo apt-get update"?

P.S. Why did you want to do a reinstall? Did flash just stop working for you? I was bitten by this problem several times recently, that's why I'm browsing here. I used remove & install, not sure whether --reinstall is equivalent. But we should handle this in a separate report, several issues in the same report are bad practice.