half works

I have dedicated two whole days on this, however without the success I was hoping for. Unfortunately i can only conclude it is not fully developed and tested. I have followed instructions religiously and read all the forum posts and reviews, triple checked all parameters and so on. Latest versions all installed. I found things that are needed but not mentioned in the poorly written instructions, typical of most stuff on the web as your know!
The problem is with the product weight/price/postcode group selection. I created post code groups for the entire UK (from TR to KW), and 1 country group for the UK which has to be done. I create an order with a delivery address in group 1 (P1) yet for no logical reason this plugin selects the price from the last group which is P5. To test this failure, I removed the entire P5 group and as anticipated APG then chose from group P4. Madness! So as I say, it half works! No good for me or my clients though, so I’m not continuing with this plugin. Sorry :-C
If someone figures this out I’d be interested to know…