>I noticed that this occured a couple of times recently.
>
>As I scroll down to look at the threads there comes a point where I see the checkbox and then nothing (no message) to the right.
>
>I have'nt noticed a pattern that can lead to this.
>
>I just wanted to let you know right away. Just in case this rings a bell.
>
>Have you done anything recently that could explain this?

This is a breakup in the connection and its transmission. I would probably wait a few days as this is probably caused by a router/ISP along the route.