Deathadder v2 right-click not working

I have an out of warranty deathadder v2 and the right-click just stopped working at all. Razer's response, 'out of warranty, you can talk to the community, that's it'. Rebooted, updated firmware, no change. It's not like a physical wear issue where it sometimes works or pressing hard can help - it just stopped doing anything. That is, until I typed this post. After trying it in a variety of things until shortly before starting this post, when I wrote the above I did it again just because and it worked for a few clicks - then stopped again.