Sliding Door Will not lock properly

Hi All,
Just managed to replace the eurocylinder lock in my slding doors (there was no key for it when I purchased the house). The onlyway to lock it was with the lever, and an auxilary foot bolt.
However, now it is fitted, I cannot seem to get it to lock properly.
The lock has two protruding bolts in the frame, and a plate inside the door which slides up and engage the bolt heads ( as opposed to most modern designs where there is a hook which hooks into the frame itself) to prevent the door opening. (i am trying to find a picture of the type of lock I have)

The problem is that when I lock the door, and locking leverl is fully down, I cannot rotate the lock fully to lock it. I have to lift the lever up slightly ( and thus the locking parts in the door, in order to rotate the lock. However this then leaves enough play in the lever to open the door!

Any ideas how I might adjust the lock to allow it to lock properly?

I have no idea how I would change the whole lock if I had to, am guessing I would have to remove the door

Cheers

pictures of door, lock and plates might help but it sounds like the door is out of line with the frame is there any adjustment on the hinges? can the lock plate be moved slightly?(some have oval holes to allow for this)