You evidently had the app, uninstalled it, and now you're trying to reinstall it. But there's still some data left over from the old installation.
If you're rooted, look in /data/data for a folder with the package name (it's in the Play store URL) and delete the entire folder.
If you're not rooted, try using adb:
adb shell rm -R -f /data/data/<packagename>
(Without the <>, where packagename is the name of the package.)
Or go to Applications, press Play Store, clear cache, clear data.