I'm not sure why it is only happening to you on this site. This forum does using AJAX -
Ajax (programming - Wikipedia, the free encyclopedia) and maybe it doesn't work well with Vista, but I don't know why that would be.
It would be frustrating. Maybe try changing your browser or writing a post in notepad and pasting it into the forum form instead of typing it straight in.
Clancy
"I like work: it fascinates me. I can sit and look at it for hours". Jerome K. Jerome