If you want to re-install Nokia Apps, you have to remove that App clean first!

After I removed "Battery Monitor" App, I still could not re-install that App again on my Nokia N97 Mini. The App's "Download" link is always grayed out in Ovi Store.

The cause is, I did not remove it cleanly. I found this key point from the following texts by Google-ing.!

Nokia Support Discussion

Betreff: Nokia battery monitor
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27-Dec-2010 11:19 AM

@aref_b

Make sure you remove everything related to the Battery monitor in Settings|Application Management|installed Apps

1. Battery Monitor Installer (left behind after install, another bug due to shoddy programming)
2. Battery Monitor
3. Battery Monitor Service

After removing all that you should be able to redownload.