I have tried a couple of experiments after finding a previously (well, what I THOUGHT was saved) saved tweaked preset.
I opened it up and found all the tweaking I had done to the effects chain, among others, was no longer there and in fact it had reverted to the factory patch.
Further I just tried it again, tweaking what I need then saving as a new name, and this file does not even appear in the list.
So what is going on with these user presets, does ST4 save them properly or not?