Thanks. I haven't so far found the config.dict file but suspect that ~/Library/Preferences/com.Infinitekind.MoneydanceOSX.plist is a historic relic because it was not recreated after I deleted it, and when I made a test pref change its modification date was not changed.
If I can find the config.dict file on my Mac will deleting it cause any other problems (eg with syncing)? I don't mind changing a few settings.
I somehow doubt the problem is due a corrupt prefs file, because if it was, then going back to build 1835 would not remove the problem, as it would still be corrupt in 1835.
EDIT config.dict is in /Users/michaelb/Library/Containers/com.infinitekind.MoneydanceOSX/Data/Library/Application Support/Moneydance/config.dict on Macs.