Andy its all here in the previous posts b t here's the summary.
First check that the release lever is working correctly in that when pulled both latches are moving to an adequate release position and the action is smooth. This to be done without hood in the closed position. if not:
Adjust each bonnet style release until both clear the spring loaded hood elements and so in theory will release the hood.
Does the cable when actuated feel smooth if tight and/or is cable catching/jamming in tube with no load?
If this seems to be correct in operation then loosen the lock nuts on the hood spring plungers and wind out the conical locating points, 2 full turns should be fine.
Now close the hood and using the lever attempt a release using Richards press on the rear rail method as you actuate the lever. You should find the hood now releases easily, if so, it's just a matter of slowly tightening the conical locators up again, say a quarter turn at a time repeating the procedure and observing the compression to the hood seal and the evenness of this between hood and body. When you get a slight compression of the seal across the car body and even spacing you should find the hood release is now working. I have found so many cars that these bonnet style catches have tightened. I'm sure the lock nuts are not correctly tightened at the factory and constant slam shutting causes one or both to over tighten until they jam.. hopefully this will sort you out, if not then a deeper investigation is required usually resulting in a new cable and routing option or rear hood catches as Dave has described.
