The key is to set to keep at most: 1
and not set it to "Keep Until I Delete", just "until space needed"
If you set to Keep Until Delete, then it will stop recording.
Pressing CLEAR will delete without confirmation, on the program list, not the program info screen.
Original S1 (Recycle Heaven)
Series 2 (PLS, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "652")
Juliet Basic (4XL, PLS)
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!