third party cookies in safari (iframe)
I ran into a problem with my authentication cookies while building a facebook appication. the cookies weren't being saved in safari.
The reason for this being that safari's default privacy setting are to disallow third party cookies (you can see this at prefrences in the cookie section).
third party cookies are cookies set by sites the user did not browse to yet did receive resources from - this could be a js file an image file or like in my situation an iframe.
The workaround to solve this was to use a 'Post' instead of a 'Get' request and on that request to set the cookies. I added a page for safari users when they logged in they were redirected to this page, this page posted back with the cookie values and then they were set. a bit of a headache but it works.
In another situation I used $.post which works too only you have to take into consideration you will have to make sure the call returns before the user makes an action that needs the cookies other wise the cookies will not be there yet.