Hi there
Take a look at the "debug" window, under the "Tools" menu, and see what the visibility reading actually is (this will be listed in the "Ambient Monitor" section at the top of the debug window).
If you really are limited to 10SM, then check your visibility options settings (under Settings menu, Visibility options): minimum surface visibility, maximum surface visibility, and maximum upper visibility. Check to see that the values are logical (e.g. min suface 0, max surface 50-75, max upper 100-150). Alternatively just use the default values, which are mentioned in the options description.
If there are still problems after that, then maybe you'll need to submit a support ticket.
Hope this helps.
Cheers,
David
