Piwik uses jQuery from:
http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js
If you are using Piwik at a SSL secured login screen, you will be prompted with the information about "The page at https://... ran insecure content from http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js".
Would be nice if you could fix this, by leaving out the "http:" like:
//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js
or setting https:// on SSL secured installations
Attachment:
ssl_error.jpg
(In [6257]) fixes #3142