It appears that this issue comes up as a result of the change that allowed images to be pasted into a plot. It has been fixed and the change has been submitted to Apple for approval. The update will appear in the AppStore as soon as it is approved (normally takes a few days).
LXBeams for iPad v1.2.6 is now available from the AppStore. If you already own LXBeams for iPad, you should be able to update your copy through the AppStore app.