I have two TiVos at present, my Roamio and a rebuilt S3.
Last night I had them both set to record the same program with the same settings (start 3 minutes ahead, end two minutes after.)
The S3 recorded the show as expected.
The Roamio's recording started about 45 seconds later than the S3's (as clocked by where the Roamio recording started as reflected on the S3's recording.)
Since both get their time base from TiVo, I've got to ask, "Huh?"
Do I need to add an extra minute of pad to the head of my Roamio recordings?