You can only filter these forced quicktime advertisements if you buy the full version off Apple. It is pretty cheap, I bought it for my Apple Mac. However if these ads are not from quicktime it may be a quicktime plugin you have, this wouldnt be solved by purchasing the full version of quicktime.
If you live in the UK you can get quicktime here -
Apple (UK and Ireland) - QuickTime
or USA here -
Apple - QuickTime