Masked downloads error

Hi

I have a standard WP 3.0.4 install with the membership plugin to protect downloadable content but have an issue with the "masked download url" which I cant resolve or find already in the forum.

As a simple example to get started I have setup some example content to be downloadable to logged in users and not for logged out users

When logged out I get the "no access" message when I click on a link to access the content, as expected. Then when I log in I still get the "no access" message , which is unexpected. If i then refresh the page the content loads.

The content loads fine then on subsequent clicks until I empty my cache. It does this in firefox, ie and chrome so there is obviously something I'm missing

Any help would be much appreciated