If you can show the page you're using it on, we can likely help. My guess (this is usually what it is) is that the other extension is including the same Javascript library that we include, in which case there will be conflicts. Usually preventing this double-inclusion is all that's necessary and normally, the other extension will continue to work normally.
Can you give the URL to your site again. I know I've seen it before, but can't remember it off-hand right now. Once we see the front-end, we can figure out the issue quickly, and then possibly poke into the AT Share extension and figure out what needs to be changed.
Finally, in the 4.0 release we're adding support for auto comments/likes in K2. We're hoping to add the same functionality to VirtueMart in the 4.1 or 4.2 release. Of course, we still won't try to break other extensions and always try to play nice when we can