First of all, sorry for a non-informative title...
(Potentially important details: r10507, Ubuntu x64, wx2.8.12, wx Project)
Let's say we have somewhere early on in the .cpp file:
BetterwxObject* Layer = NULL;
If we hover over the "Layer", we get the proper tooltip
So far so good. And for many more occurences of this "Layer" variable.
Until, several screens lower, we stumble upon this:
if (!SomeBoolean && Layer)
After this line comes into view (and maybe hoverting over the Layer in this line), the Layer tooltip permanently (until restart) gets ruined into: