I think its a webpage writing error. I remember back in the old days of writing webpages we had to test the page on a number of browsers to make sure it was shown correctly on them all.
It could also be the way how the font size relates to the browsers current settings. There is a way to force the browser to display at a set size.
If I keep getting issues with BT / OR websites I might apply to write them lol
![Grin ;D](https://forum.kitz.co.uk/Smileys/kitzemotes/grin.gif)