Definitely check out the PS as already detailed.
I think it's a signal problem. High and growing RS counts are a primary indicator of signal problems, although I guess I couldn't rule out the PS (so check it).
ideal signal levels per TiVo support pages are in the range 80-99. The signal level pegs at 100, so a reading of 100 could mean something a lot higher, and it is possible for excessively high signals to cause errors -- and eventually damage your tuner circuit elements. The coincidence with starting your VOIP service makes me suspicious of signal problems.
I had a channel frequency that was always low and pixelated. The service tech used his meter to check the signals and said he couldn't find any problem -- including on the exact offending frequency. He did this again on the second service call. Then, just as a precaution, he tightened the cable connections at my tap out by the street and that fixed it. So I don't put a lot of faith in their signal quality checks. I don't know if it's the meter or the tech which isn't sophisticated enough.