The Floor of the Bar in Season Four?

"This is the season where somebody did that happen without us realize it," says co-star Meg Ryan. "We didn't realize, you know, cause you're not doing a million things until we got into the editing room." The floor of D's bar was changed from parquet to flat brown wood planks in order to save money and brighten up the apartment. It took four seasons before they were able to get back on track with the design.