Living the beta tester life isn't always great as witnessed by some of the recent beta releases of WhatsApp, which many in the CrackBerry Forums members claim have had a few issues causing laggy performance and app hanging issues. The good thing though is that WhatsApp is incredibly fast at updating their betas and when issues arise, a new build is never far off and such is the case right now.
A new beta build is available from the Beta Zone that notably aims to correct an issue where the app could hang while trying to index certain messages for chat search. If you have the Beta Zone app installed, you should see the update listed and available for download. If you're new to the Beta Zone, be sure to grab the Beta Zone app and sign up. It will be needed to access this release.