Sorry about the delay but we have gotten to the bottom of the issue.
The bug you reported occurs for recordings that are created on your PVR and sent up to our server, it does not effect single, keyword or series recordings created on our website.
This is a server-side issue and is long standing but recently uncovered, thanks for the helping hand.

I have corrected the problem and updated the production servers, I have also tested the fix with the app in my simulator using the authentication token from your account and I can see that your single recordings now have delete buttons as intended.
There is a second issue that prevents the "My Week" list from showing the device that single recordings (both PVR and server-based) are scheduled for, I am working on that one next.
Let us know if you find any other issues.