|Most likely it is a website error. |
If you are using IE do this:
Tools > Internet Options > Advanced tab.
Under Browsing ensure any script debugging is disabled (checked).
Otherwise it could be worth seeing if it does it using Firefox (it could prove something).
I have found some websites which work better on Firefox than IE and vice versa - perhaps one of several reasons for having an alternative browser around.
Always pop back and let us know the outcome - thanks