rosie
if it's a familiar page
try waiting a second or two before you start clicking round (it will say "done" bottom left)
often with a java scripty page if you click before all the beans (bits of code) have loaded the browser will stick in the error state.
either that or hitting a link as soon as the page appears
good advice lone - a new browser is always a good solution (at least until it downloads - how about a restore while she's waiting?)
oops
too quick meant to add ....
the java thing has always been there - but a recent hotfix from microsoft has increased the security - but increased the load time as well - if it sees partial code it locks the browser ...
(have you had a warning about page containing java poping up recently)?