In safari browser, If you click Develop->Start Debugging Javascript->Resources, any action taken in the site is logged twice in piwik
This is probably a symptom of how safari's debugging works, but it would be nice if Piwik had a config option to ignore page refreshes. This is more of a major problem because Goals (if set to multi) will be converted twice also.
Sorry, this would have to be considered a Safari bug/feature.