RDi loses sensitivity to context

Why does it happen that, just as I start RDi, it all goes well when you
hover on any symbol with the mouse, and it reacts telling you what it is
and where it is declared and the type it is. All of a sudden, it stops
doing that. Not even the Outline is shown. Why is this? Is that memory
exhausting?

What should I do to get it to recover sensitivity to context without having
to shutdown and restart?

Thanks.

Javier Sanchez