Of course it's not a huge problem because Safari seems to work fine with the apple store, but, ironically, according to apple, store.apple.com doesn't support the use of safari on their site.
From the Apple store:
Edit: link is here
From the Apple store:
Do I need a specific browser to shop in the Apple Store?
To shop in the Apple Store you need one of these browsers:
Netscape Navigator 3.0 or later for Macintosh or Windows
Microsoft Internet Explorer 3.x or later for Macintosh or Windows
AOL 3.0.1 or later
For a better shopping experience, we recommend that you use Netscape Navigator 4.x or later or Microsoft internet Explorer 4.x or later
Edit: link is here