Greetings,I asked my problem (the follow issue):
Problem: Mobile site is displayed on my desktop browser.In your FAQ For some reason your browser is detected as a mobile browser. A browser add-on could cause this.
I do not have any add-on.I report my information.
a. Does error happen with different browsers?
→　No. Only Safari in MacOS X    IE OK,Firefox OK,Chrome OK.
b. Which URL you use to access your site?
→　www.equus.co.jp/top.html
c. Is your site public so we can test it?
→　Sure. Please test it.
d. Can you tell me your browser user agent (use whatsmyuseragent.com/ )
→　I report the follow user agent (2).
    Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_4_11; ja- jp) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/4.1.3 Safari/ 533.19.4
    Mozilla/5.0 (Macintosh; PPC Mac OS X 10_5_8) AppleWebKit/534.50.2 (KHTML, like Gecko) Version/5.0.6 Safari/533.22.3

Thank you for your cooperation.

I had the same problem - turns out I was using the same 'alias'in my home menu link as in my mobile menu link - I changed my mobile home menu item to alias 'mobile-home' & the problem went away

Check your safari developer menu. You may have changed your user agent there. If setting is default or anything automatic, change it to whatever you wish but not some mobile agent. You can also add more agents.

You need to check what user agent you are getting when you open that in safari and then make the settings accordingly in the administrative panel.

You can simply put up the test file named test.php as under and check that out.

<?php
echo $_SERVER['HTTP_USER_AGENT'] . "\n\n";

$browser = get_browser(null, true);
print_r($browser);
?>

before you do all that make sure you don `t have the same alias on your mobile menu items as you do on your desktop menu items - that`s all it was for me

Thank you very much for your reply.I checked my mobile-menu, and changed its alias.But the mobile site has been displayed on my desktop browser (MacOSX Safari) .

Thank you very much for your reply.It is good for changing my user agent in safari.I can see the desktop site in my browser ( MacOS X, safari).
But I would like to see the desktop site in my safari ( user agent = default agent ).

Thank you.
I have put the "test.php" in my server.
I checked my user agent.
Of course, 
Mozilla/5.0 (Macintosh; PPC Mac OS X 10_5_8) AppleWebKit/534.50.2 (KHTML, like Gecko) Version/5.0.6 Safari/533.22.3 .

Try to clear browser's cookies (it maybe that you preview mobile version in browser, and last used mode had been saved in cookies).

I had cleared my browser's cookies and caches (all).
But mobile site is dosplayed on my desktop browser (MacOS X Safari).