Actually while there is no resume option while a program is still recording pressing the play button on the remote control works as a defacto resume button. I only discovered this recently when it was posted in another thread a while ago. And I used this often and successfully during the recent March Madness basketball tournament.
I think I have now found that with the latest SW (do no know the Version No.) you can:
1. Start a REC
2. Pause the REC
3. Enter another channel number numerically to go to another Live Program on another Tuner
4. Click DVR
5. Select the REC you started first and you WILL see the RESUME option along with Join Live and From the Start Options