I never have a problem with this on any of my receivers. I FFWD on X3 and as soon as the show starts again I hit play and it automatically backs up about 10 seconds and starts from there (usually about the end of the last commercial).I HATE, HATE.............HATE Direct TV !!!!
We had Dish Network and I loved it.
Direct TV stalls left and right, when you fast forward your DVR and then push play, its delayed about 15-20 seconds or more behind, where you stopped it. For instance, when your fastforwarding and you see where your movie resumes after the commercial and you push play, it starts back in the middle of the commercial before the movie resumed.
Direct TV will not go to the closest channel when you try to manual enter a channel. All you get it a beep and a window pops up that says "Channel not available" Dish Network will automatically move you to the closest channel to it.
My HD DVR receivers have been slow as shit lately, but it usually speeds up and gets back normal after a day or two. There's actually some extremely troubleshooting and tech advice on the DTV forums on their website if you ever run into issues.