%order-history doesn't redirect correctly

When I put the return url in as '%order-history' as suggested for paypal or other payment gateways, it sends me to 'www.mysite.com/%25order-history' and produces a 404 error.

I can view the order history if I type in www.mysite.com/user/1/store

the error keeps happening even if I change the line
drupal_goto(variable_get('ec_receipt_return_url', '%order-history'));
to
drupal_goto(variable_get('%order-history', '%order-history'));
(so it's not to do with url encoding upon saving the settings form or something like that)

I'm using drupal 5.5 and this error occurs in ec 4 alpha 6 as well as dev version. I don't know where the problem would reside exactly so I filed this under paypal...