With the social Tracking one specific bug bit me the other day. Google Analytics won't apply hostname filter's to the social interactions, and it may cause profiles that are filtered to only include traffic to domain A, showing social interactions for domain B. From there all sorts of bad things follow: 0 pageview visits, lower pages/visit and so on.
At first I thought about disabling the socialTracking on the +1 buttons, but it seems that the API don't support it yet. But I found an undocumented feature to disable it. Now you can disable the socialtracking on the +1 button and use Events instead, since they go through the filters before showing up in your Google Analytics profile.
You'll only want to use it if you are having problems with social tracking and hostnames filter. Otherwise the default behavior is way better since it will populate in separate Social reports.
If you are using the asynchronous code for Google +1 button, loading the syntax is a little bit different.
Thanks Fábio Phms.