Retractable door issue with opener

Hi,

I wonder if someone can assist me...

I recently bought a house that has a manual double garage door with a retractable frame fitted in 2003.
 
I have just started installing an electric door opener (a Foresee 350G) and have discovered a problem. When the garage is opened using the manual T-handle the door area (marked with the red arrow in the attached diagram/picture) easily clears the long plates on either side of frame (as the door is 'lifted up'), however when pulling the garage door from the top (using the Foresee's ‘hockey stick’) the door is forced against the long plates on either side and the door is very difficult to pull open.
 
I am concerned that the opener will struggle to open the door or a ‘too much force’ trigger will occur stopping the opener. Once it has door has lifted up sufficiently, the door opens easily the rest of the way.
 
This looks like it would be a standard problem with this set up. Has any one come across it before and if so how have you solved it? Is it as simple as re-tensioning the springs? Or is this door unsuitable for an opener?
   
Apart from this issue, the door is working well and seems well balanced.

Many thanks in advance for any advice given.

Ian