Will look into this and see why it is happening .
Have you tryed loging out from the forum , then loging back in ?
Used a test account and it did work - had remember me checked .
This may be a glich in the store with logins and new registrations . and will wright to the author .
Also could try loging in at the store if it still wont' work .
http://gfxstyles.com/GFXStore/