In jQuery-Pagebar 0.3.2.1, when you have an URL like this:
http://example.com?something=foobar
the plugin creates this URL:
http://example.com?something=foobar?paged=5
which should be
http://example.com?something=foobar&paged=5.
There is a simple fix that should solve this problem for good:
In jquery_pagebar.php,
find this code (line 148):
if(get_option('permalink_structure') != "") {
if (is_search()) {
$loc_href = '\''. $url .'&paged=\'+ ui.value ;';
}else {
$loc_href = '\''. $url .'?paged=\'+ ui.value ;';
}
} else {
if (is_search() or is_archive()) {
$loc_href = '\''. $url .'&paged=\'+ ui.value ;';
} else {
$loc_href = '\''. $url .'/?paged=\'+ ui.value ;';
}
}
and replace it with this:
if ( false === strpos($url, '?') )
$loc_href = '\''. $url .'?paged=\'+ ui.value ;';
else
$loc_href = '\''. $url .'&paged=\'+ ui.value ;';