[dartho]

Try this on for size:

In AdminCP->Plugins & Products->Add New Plugin create a new plugin for product: vBulletin, hook location: style_fetch, Title: Mobile Detection, Execution Order: 5 Code:

PHP Code:

$mobile_style_advanced=10;  //iPhone?
$mobile_style=10; //Any mobile phone/device
$default_style=6; //Your default or preferred desktop style
$vbulletin->input->clean_array_gpc('c', array( 
    COOKIE_PREFIX . 'userstyleid'     => TYPE_UINT, 
    COOKIE_PREFIX . 'skipmobilestyle' => TYPE_BOOL, 
)); 

$my_skipmobile = $vbulletin->GPC[COOKIE_PREFIX . 'skipmobilestyle'];
$my_userstyleid = $vbulletin->GPC[COOKIE_PREFIX . 'userstyleid'];

// Test mobile browser 
$mobile_browser = false; 
$mobile_browser_advanced = false; 
//if ($vbulletin->options['mob_detect_enabled']) 
if (1==1)
{ 
    if (stripos($_SERVER['HTTP_USER_AGENT'], 'windows') === false) 
    { 
        if ( 
            preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|android)/i', strtolower($_SERVER['HTTP_USER_AGENT'])) 
            OR 
            stripos($_SERVER['HTTP_ACCEPT'],'application/vnd.wap.xhtml+xml') !== false 
            OR 
            ((isset($_SERVER['HTTP_X_WAP_PROFILE']) OR isset($_SERVER['HTTP_PROFILE']))) 
            OR 
            stripos($_SERVER['ALL_HTTP'],'OperaMini') !== false 
        ) 
        { 
            $mobile_browser = true; 
        } 
        // This array is big and may be bigger later on. So we move it to a second if. 
        elseif (in_array( 
                    strtolower(substr($_SERVER['HTTP_USER_AGENT'], 0, 4)), 
                    array( 
                    'w3c ','acs-','alav','alca','amoi','audi','avan','benq','bird','blac', 
                    'blaz','brew','cell','cldc','cmd-','dang','doco','eric','hipt','inno', 
                    'ipaq','java','jigs','kddi','keji','leno','lg-c','lg-d','lg-g','lge-', 
                    'maui','maxo','midp','mits','mmef','mobi','mot-','moto','mwbp','nec-', 
                    'newt','noki','oper','palm','pana','pant','phil','play','port','prox', 
                    'qwap','sage','sams','sany','sch-','sec-','send','seri','sgh-','shar', 
                    'sie-','siem','smal','smar','sony','sph-','symb','t-mo','teli','tim-', 
                    'tosh','tsm-','upg1','upsi','vk-v','voda','wap-','wapa','wapi','wapp', 
                    'wapr','webc','winw','winw','xda ','xda-') 
                ) 
            ) 
        { 
            $mobile_browser = true; 
        } 
    } 

    if ( 
        $mobile_browser 
        AND 
        preg_match('/(ipad|ipod|iphone|blackberry|android|pre\/|palm os|palm|hiptop|avantgo|plucker|xiino|blazer|elaine)/i', strtolower($_SERVER['HTTP_USER_AGENT'])) 
    ) 
    { 
        $mobile_browser_advanced = true; 
    } 
} 
$vbulletin->input->clean_array_gpc('r', array( 
    'styleid' => TYPE_INT, 
    'langid'  => TYPE_INT, 
)); 

// Set up user's chosen style 
if ($vbulletin->GPC['styleid'])
{ 
    $styleid = $vbulletin->GPC['styleid']; 
    vbsetcookie('userstyleid', $styleid); 
    if ($styleid == $default_style) 
    { 
        vbsetcookie('skipmobilestyle', 1); 
        $vbulletin->GPC[COOKIE_PREFIX . 'skipmobilestyle'] = 1; 
        $my_skipmobile=1;
    } 
    elseif ($styleid == $mobile_style) 
    { 
        vbsetcookie('skipmobilestyle', 0); 
        $vbulletin->GPC[COOKIE_PREFIX . 'skipmobilestyle'] = 0; 
        $my_skipmobile = 1;
    } 
} 
elseif ($mobile_browser_advanced && !$my_skipmobile) 
{ 
    $styleid = $mobile_style_advanced; 
} 
elseif ($mobile_browser &&!$my_skipmobile) 
{ 
    $styleid = $mobile_style; 
} 
elseif ($my_userstyleid) 
{ 
    $styleid = $my_userstyleid; 
} 
else 
{ 
    $styleid = -1; 
} 


edit the first 3 lines of the plugin code to suit your purposes (should be self explanatory) and see how you go. Make sure you disable any mobile detect type scripts/plugins you may have running such as the one you linked to in your last post whilst testing this. Also be aware that you should probably do testing under a standard user account as administrator accounts have different permissions when it comes to style selections.

Please feedback how it goes.