that it happened gradually over time made me look for a file that would accumulate data and survive a update of packages. what i found was .webkitcookies. and after nuking that, webkit was blazingly fast again!!! yes people, that means one have to log back into forums and similar...
cp ~/.webkitcookies ~/.webkitcookies.old egrep -i '^[^[:space:]]*(maemo\.org|internettablettalk\.com|google\.com|yahoo\.com)[[:space:]][[:space:]]*(TRUE|FALSE)[[:space:]]' ~/.webkitcookies.old > ~/.webkitcookies rm ~/.webkitcookies.old
cp ~/.webkitcookies ~/.webkitcookies.old egrep -v -i '^[^[:space:]]*(interclick\.com|advertising\.com|doubleclick\.com|specificclick\.com)[[:space:]][[:space:]]*(TRUE|FALSE)[[:space:]]' ~/.webkitcookies.old > ~/.webkitcookies rm ~/.webkitcookies.old