With the attached system, the liveness checker claims that the property "E[] true" is not true. This is obviously not correct.
Created attachment 28 [details] Test case
A fix has been checked into CVS. The bug made the old implementation an under approximation. I.e. when E[] p returned true (or A<> p returned false) this was correct, but when E[] p returned false (or A<> p returned true) this might have been wrong.