We released an update on 10/19 that resolved several issues with iOS 5. You can view the full release notes here:
viewtopic.php?f=2&t=771Most users are able to install it simply by launching the app and letting it update. If the update is not completing for you, then launch the iPhone's
Settings app, select
Safari, and tap the buttons to clear your history, cookies, and data. VoiceCentral will download the latest version the next time you launch it, which will require you to enter your login details again.