The share is grayed out on my ride from this morning and the last few activities. That's as far back as I checked. I haven't used it but I'm pretty sure it was available yesterday. I changed my privacy settings both ways and neither was helped.
I'm seeing strange behaviour with using FireFox 3.0.10 right now. But no issues with Safari 4. Can you try Safari to see if the experience is any different?
It sounds like you are restricted with you can and cannot do at work. Do you know if there are proxy settings or restrictions placed at the network layer as to what is allowed or what is not allowed? Sounds like it might be an issue outside of Garmin and Connect, but am certainly not ruling that out since Safari works well for me and FireFox is slow.
It's not really that I'm restricted it's that updating browsers isn't always a quick process and sometimes is not really worth it. Either way the problem has been solved with the toggling of the privacy setting at the activity level.