share This tool integration
Design and Skin Customization
My guess would be that the variable $item is not available in the feedback.tpl template.
Try adding the function to your skins/jrBeatSlinger/jrAudio_item_detail.tpl file.
The only problem with this is that you will most likely have two sets of buttons because the detail page features, ie. comments, sharethis, tags etc... are added via a function:
Bottom of the jrAudio_item_detail.tpl
{jrCore_item_detail_features module="jrAudio" item=$item}
You can arrange the order of the detail features in your ACP here:
/core/module_detail_features
I'm not aware of a way to exclude the ShareThis module from the jrCore_item_detail_features function.
Hope this helps!