Sorry to hear that, Nick. (Quickly scanning your list of names to make sure none of mine match.......phew! No, not to blame!!

)
It is annoying, though, just when you get all excited about finding a contact, then, nothing..... Must admit, most of my contacts through Genes have been very distant, second marriages or in-laws etc, so don't matter so much. And often, when I'm given access to others' trees, I've usually got to a similar point or further back.
I always make a point of replying to contacts, even if it's just a "Sorry, not got much about this line as it's not one of my direct ones," and passing on what little I might have, or other links, or whatever.
I've only once not replied to a Genes contact. I was once contacted by a lady and shared everything I had. A couple of weeks later a man contacted me with loads of my rellies. When I checked it was just a straight rip off of the previous lady's tree, right down to incorrect spellings and minor inconsistencies. Avoided him like the plague and never heard another thing.
Hope you've had chance to calm down and take it with a pinch of salt, that GREAT contact is just around the corner.

Sally