On my first attempt to download updates to my new Navionics South card, I got this message, "sorry, your chip doesn't have enough free space" I contacted their customer service, and this was their response.
Unfortunately, we have found an issue with the current HotMaps Platinum South cards. To resolve this issue, we will send you a replacement MSD/HMPT-S6 card at no charge. In the package, there will be a pre-paid self addressed envelope for you to send back the defective card.
Please provide your mailing address, and shipping address (if different), as well as your contact phone number so we can process the exchange.
Also, please provide the make and model of the GPS plotter that you are using.
If you need any additional information, please do not hesitate to ask.
Kevin Blakey
Customer Service
It's always a pain to have problems with something new, but it's good to know they stand behind their product.