Pixela will only burn on '-' type discs.
OK, 2 things:
1. Go to the site and update the software, which is dated April 25th (the other version - which is later - isn't for the HF10/100). Looks like it adds a box telling you it's loading stuff, instead of leaving you hanging. Still takes an ice age to load an 9Gb file.....
2. In order to write back to a disc, from what I can see from my quick fiddling just now, you need to drop the files (editied or otherwise I would assume) into either the AVCHD or DVD list on the botton left of the window. Highlight the project and hit "write". From there you should be able to select your burner etc.
Vizio M80-C3, Denon X6300H, Emotiva UPA5 (triggered), Wharfedale Pacific Evo 40s, CS, 10s, PC DX12 sub, Def Tech A60 Atmos tops, the internet, an ASUS ChromeBox running Kodi, a TiVo Series 3 and a Philips BDP7501 UHD . There's also a Wii, but we don't talk about that...