Hi, I've just started using Money for the iPhone and have experience the same problem with a category disappearing after either editing it or opening it to add or edit a sub-category. I have also had the situation of having created a sub-categeory, when I went back to edit it, it was no longer showing, but if I tried to add it back again I got a message to say it already existed. On that occasion I added 2 other sub-categories and on going 'back' to the main (parent) category screen, the parent I had been working had then disappeared.
It would appear that the disappearance of these categories and/or sub-categories does not effect the transactions linked too them. Could you please confirm that this is the case, that also no other data is being lost, and that the only work-around at present is to re-create those categories that have disappeared (given we recall what they were).
I spent some time selecting Money from the many available apps in this area based on the functionality it provided, I have to say though that this is a serious fault that appears to be taking a long time to be addressed, so I would not recommend this app to anyone until this is corrected.
In general it would be helpful if we were given a clear understanding of where you are at with this, what if anything is known to cause the problem (so users can attempt to avoid the situation), the impact it does or doesn't otherwise have and any recommended workarounds to deal with the problem whilst it is being fixed.
Thanks, Lex