Thanks Leon, Richard, Ian, Malcolm, Martin, Derek, Tim, Aleksandr, Margarity, and Adrian for you methods on bringing in a file list. Ian especially as this trick is neat and I'm sure many of us Query Analyzer users were unaware of it. Tim's advice never to use select * is well worth considering. Carl, thanks for the direction on using ms SQL server management studio, I don't have that but your comments should help those that do. Kll, thanks for highlighting the issue also effects views also backed up by Thomas and several others.
Tony.dyer, I'm suggesting that yes you would need to rebuild the overarching function, as the same principle applies, the columns list is built when it is compiled. Naresh, the way to refresh the function is by recreating it, but if you have used select * prolifically, you may have problems finding them all quick enough not to cause problems, better not to use select * I think.
Tore you comments on SQL Prompt, I'm guessing this needs your database to have its relationships defined, sadly my supplier didn't supply that, but it sounds very useful, thanks. For those that don't know SQL Prompt is a product by Redgate.
Sammesel, thanks for raising the use of sp_depends, I've looked at this before but found it short, since my functions are stored in a separate database to the data, and it doesn't work across databases (well not so as I've seen), and Derek thanks also for showing some issues with this. Harshil_sutaria, yes we could just recompile, but by being specific about fields, and using Ian's suggestion to make this easy, we save a lot of trouble and remove risk.
Adrian, another great tip, and something I try to always do, the prefixing of column names. We abbreviate all our prefixes, based on part of the table name, which is quicker than typing the whole and still easy to identify, at least a lot easier than the prefixes some use, of a, b, c, etc, which means you still have to look through your join logic to see which table your prefix is for. Luckily our tables allow a standard set of easy to identify prefixes, you may not be so lucky of course.
Matteo, thanks for the comments on sp_refreshView, I've not used views myself, but I'm sure this will come in handy at some point. David, you update statistics is good advice, I've seen a database application die because someone had stopped refreshing statistics, soon was fixed, but didn't look good.
To all, thanks for your comments regardless, as we all value from your input and it is much appreciated.