Those titles only ran for 5 days. They began with the first ever Bigger Breakfast on the day the 1997 - 2000 theme music was launched. (Late May 1997. I think this clip is from the show:
https://www.youtube.com/watch?v=uYlDFqGYKYE. Doesn't feature those credits though, sadly.)
On the Monday, the new theme accompanied the opening titles but it was a basic version of it, without many of the elements that subsequently featured. (That is, the theme accompanying the opening titles from autumn 1997 to spring 2000.)
However, from the Tuesday to the Friday, the 1996 theme was back for the opening, whilst the new theme featured into and out of breaks. (Not sure which theme was used at the close of the show. There were new closing titles made up of the 1992 - 1996 into/out of breaks and stings and incorporating the new theme - if they didn't launch this week, it'll have been the week after.)
Then, when the show returned to the house the following week, there were new, shorter opening titles which featured the new theme. (These were the titles that didn't really feature the house.) I'd be interested to hear the first, basic version of the 1997 theme over the first Bigger Breakfast's opening should this ever turn up.