You are lucky atleast your reported bug is fixed.. I am using Version for MAC and when Web access is on, it takes huge memory (100GB+), crippling my complete machine. I reported it several time and nothing has been heard neither it is fixed.
Regarding upgrade Charges. This is the cheapest invoicing software, which I found for MAC Machines, with CSV import and Web Interface (Many bugs in it, like memory hogging, you can't change currency and as I have two companies setup. you can't change that either. More importantly, There should be some kind of Archieve invoices option for sure. We sell on ebay, items costing 1-2-3£ so we have plenty of invoices and that slows down whole software.