I wonder whether anyone else has observed the following or perhaps has a different view?
Having lately had a problem with the the text labels on new buttons not being correctly vertically centred in FMWebDirect on Safari 7.0.4 I discovered that if I changed the layout to use an earlier version of my theme the problem disappeared.
More specifically - the style I created locally - i.e. it is a local theme until it and any current amendments have been saved to the current page theme - worked correctly until I saved it to the current theme - when lost its vertical centreing - when viewed in FMWebDirect.
When I changed the page to use an earlier version of my theme - and repeated the same steps - the style worked as expected after it had ceased to be a local style and was incorporated into the current page theme - in this case my earlier version of my theme.
From this I deduce that the later version of my theme has become corrupt - so that it prevents the relevent style being rendered correctly when saved to the theme.
So my conclusion is that it may prove good practice to save new versions of one's hard won custom themes on a regular basis - so that the process of reverting to an earlier one is not too painful - although I am not looking forward to changing the theme of every layout to the theme that works as expected.
Interested to hear your observations on this?