Thanks to EBF on TiVoCommunity.com:
If you go to the To Do List and find a show that will be clipped (marked with a * next to the time). Select the program and pick Change Recording Options. Under Start/Stop Recording you should see that the show will be clipped. Change this to Start/Stop On Time. Save your changes. You should then see the conflict confirmation screen offering to clip the other show. Now the other show will be the one clipped instead!
That’s a pretty neat trick. Especially when the end of a program is going to be clipped – usually better to clip the start of the next instead.
