slow vídeos

hi guys......lately i've been having trouble viewing youtube vídeos, it's taking a very long time to buffering and it's not a problem with the internet, cause i can view vídeos from other sources at a normal speed , the only thing i can relate it to, is that a few months ago i installed vector works and Vuse .....is there chance that one of those programs is causing the problem, or could it something else? ....thanxx

anyone