Installing the OS X Lion Update 10.7.3 (Client Combo) re installs the App Store for you which may help.
Restart your Mac after the combo is installed, launch the App Store, try writing a review.
It's ok to do this even though you are already running v10.7.3
If that didn't help, quit the App Store.
Go to ~/Library/Caches/com.apple.appstore/Cache.db
Move the Cache.db file to the Trash.
Relaunch the App Store, try again.
~ (Tilde) character represents the Home folder.
For Lion: To find the Home folder in OS X Lion, open the Finder, hold the Option key, and choose Go > Library
I regular look´s after updates for my machine, and funny enough there was one after i wrote this discussion, i not sure what is was called but now both reviews in app store works again, beside everything run´s faster.
Thanks for the fast reply anyway :-)