NEVER happened to me while I was flying (now not for 15 years or so) nor to anyone on any frequency I was monitoring. Obviously there are procedures for what to do if you lose communications with ATC (follow flight plan, duh, that's what it's there for) but I never lost communications when I was IFR, and I don't recall ever hearing ATC having a hard time raising someone else on the the frequency. Maybe things are different now, or here in the northeast?
BTW, my instrument instructor was one of those guys Reagan fired, a senior guy at NY Center. We talked about a lot of stuff, but I don't recall his ever having talked about having trouble talking to flights he was supposed to be controlling.
ML/NJ
I have seen it many times.