Downloading some pdf files not possible

Help please! I can't download my account statements from my online banking (ING Germany). everytime i click download, the download window appears but its empty, meaning no file size, estimated download time etc. the same just lately applied to a HP support chat. as soon as i uninstall norton 360, the download is working fine. other downloads are not affected. do i have to change some settings in the firewall?

 

I am using vista home, norton 360 v2.5.0.5

 

Thanks for any suggestion!