404 error order link

[tigersoft_hun]

Virtuemart (2.6.14), Joomla (2.5.28):

1. Registered user places confirmed order. #XXXXXXXX
2. Registered user receives confirmation email with invoice and button that links to order. (example) http://www.yyyyyyyyyyyy.com/index.php?option=com_virtuemart&view=orders&layout=details&order_number=XXXXXXXX&order_pass=p_12345. Clicking this button works fine regardless whether Virtuemart SEF is enabled or not
3. Registered user accesses his Virtuemart user account page to view previous orders
4. Registered user clicks "List orders" tabs and a list of orders comes up
5. Registered user clicks order number (#XXXXXXXX) from list and 404 error comes up. http://www.yyyyyyyyyyyy.com/orders/number/XXXXXXXX = 404 error

If I turn Virtuemart SEF off, all works correctly.

I don't know what's the problem....