yeah agreed, the VH45 has a few issues, i have had a few infinitys through that have shat themselves all with chain guide issues which have ended in catastrophic engine failure... if you belive it is only isolated feel free to read this forum (infinity forum) which outlines the issue in great detail.
once you determine which year you engine is and whether or not is has had the guides done then yes they are a killer engine, if not the are pretty much a time bomb.
http://forums.nicoclub.com/zerothread?id=25201