Media convertor problems?

On Oct 11 I had some connectivity problems, thought there was some router problem, but finally suspected local (PC) router and media convertor. Once again, on Oct 23, I had one more episode of connection problem. Tried restarting my router (Millenium) computer. Still problem persisted. Then toggled the WorkStation/Hub switch of the media convertor. Then it started working. So, probably media-convertor / network card issue. Right now it is working and I can live with it....