Hi,
see here notes about HTML5 fullscreen:
http://krpano.com/docu/actions/#fullscreen
That means when the real HTML5 fullscreen mode is NOT supported (e.g. like in the Android WebView browsers), then the krpano viewer tries to resize and position itself to cover the full page. But this can be problematic and conflicting on complex html pages of course.
Additionally the stock/WebView-based Android browsers itself are very buggy and unreliable regarding CSS3D, many display errors are related to this. The Android Chrome browser is better here, there also the HTML5 fullscreen-mode is supported.
An other page design where the pano will be opened in a new browser window/tab would be probably the better solution...
Best regards,
Klaus