Hi,
It seems there's a bug in JoomSEF that causes the sid variable to be treated as non-SEF. We'll fix it in next version.
In the meantime, you can open the /components/com_sef/joomsef.php file and remove the two lines around line number 383:
$sid = $uri->getVar('sid');
if (!$sefConfig->dontRemoveSid) $uri->delVar('sid');
Of course make a backup of the file before doing this in case something goes wrong.
I can also do this for you if you can send me FTP access credentials to your website to
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