Did you solder the inner conductor of the cable to the centre pin of the plug? People say "you don't need to" and "you can get away without", but I never trust things like that and you leave yourself open to all sorts of odd faults somewhere down the line. Of course it will work for some people, which is why they misguidedly swear by doing it that way, but I think it's b@ll@cks.
In any case, it is a better idea to use F connectors on the cable (which makes using splitters easy - see below) and fit F-Belling adapters where needed. Then you get a much better overall result with no soldering and no dodgy connections.
Oh and don't use cr@p cable. Foam filled CT100 (WF100) with a proper overall copper (not aluminium) screen is what you should use.