I will run some tests this end but can you try something for me, do all the things you decribe at in your post but when finished go to the maintenance page, near the bottom is a few fields I need the details from,
Is in transaction should be No but I am guessing it is yes, if it is can I have the transaction name in the field below, what my guess is going on is you have an open transaction somewhere in the code this is not allowing you to save data once this is opened and left opened, if it does have something in that field let me know what it is and then press the button "Commit transaction" this will save pending updates and I will fix this properly.
atb
alex