smart resume stopping too soon

I have a problem that appears to be VERY common with Xfinity users, but one that Xfinity either does not understand, or simply does not care to fix. It has been going on for a long, long time, yet nothing seems to get fixed. I am getting tired of dealing with it and am just about ready to switch providers over it. I did not have this problem with Direct TV, for example. The problem is that when I record a program, it starts recording some 40 seconds before the program actually starts. In addition, when I hit fast forward to skip over the ads, it stops some 40 seconds before the program actually starts. That means that I have to either watch the 40 seconds of commercials or hit the fast forward button again. The really, really annoying thing is that if I hit the fast forward button immediately, it stops again. I actually have to wait one or two seconds before hitting fast forward. This sort of thing is happening to a lot of Xfinity customers and it NEVER gets fixed. This is not rocket science, so I can't figure out why they can't get it right. With Direct TV, a recording not only stops in the right place, but it automatically skips over the ads and then stops when the program begins. I don't have to manually hit the fast forward button. Why can't Xfinity do the same thing? If Xfinity can't figure out how to fix this for me, I am going to switch back to Direct TV. GRRRRRR!!!!!