Nokia updated the Nokia Store client for S^1 phones from version 1.16 to 1.22.
This new update is supposed to fix some SSOUI running amok issues as well as speed and cache improvements. The 1MB update can be installed just by opening the Store client on your phone. If the updates does not present itself immediately it may take a little while for it to be available to your region.
Source: SymbianTweet