I do all my banking online, but have recently run into trouble because my computer suddenly won't open the website for my bank (Westpac), regardless of whether I use Mozilla or IE.
It acts likes it's going to open it - the tab has the loading symbol happening, and at the bottom it says its transferring data, but it will do that all day long.
I can open any other website with no problems other than occasionally noticing that some pages have a missing component. As you would imagine, I usually don't know when this is happening, unless a form is missing or the PC next to mine is on the same page. I don't know if these two problems are linked, but don't think so since the missing bits thing has been going on for ages whilst the won't-open-Westpac thing is a new event.