While Phil has a point that there probably is a deeper root problem (generally user related) the fact is that deleting the .upf corrects more things than it doesn't and when you are trying to get back into production it is usually best to fix first and ask questions later. Same goes for deleting .rsc files in Geopak. While it shouldn't make much difference it general does.
I have a couple of Service Requests, where the solution of the problem was to delete the .upf file. Probably this is what support likes best - it's the easiest solution for them. But I do agree that someone should dig deeper into the system.
P.S.: As far as I know the .upf files also store the version number of the application used. Which should prohibit problems arising from other, older MS versions.
WRT <One of the main problems here is a corrupted user preference file>, UPFs often get *blamed* for a lot of things -- in fact, it wouldn't surprise me if they were seen as the cause for sun spots :). Seriously, that *blame* is very often misdirected. How? Well... there's a very big difference between cause and effect. Alleviating the effect (deleting the UPF, for example) does little (if anything) to remedy the cause, which could be something much deeper and many times more serious (_that_ is what needs to be be figured out... deleting a UPF certainly won't do much than sweep the real cause under the carpet). The cause could come from any number of sources, which is why it is so important to find out what led up to it. It's like a broken window -- a window usually doesn't *break* itself -- something else is 99.999% the culprit. If other things happen due to the window being broken, that still is no indication that the window broke itself. There's a very distinct difference there. Solving what broke the window is well worth every minute of investigation -- and often makes things work much better all around.