Amritas links to The Darkest Days and asks, “but what's with all the vowels”?
If I knew something about Ukrainian, Polish (the region was once ruled by Poland), and Yiddish, maybe I could work out the mystery of the double names for Kolomyja/Kolomeya (j is just another spelling of the sound [y], so it's no big deal, but was e a Yiddish substitute for the y vowel?) and Dunaivci/Dinavitz (c and tz are probably just different spellings for the sound [ts], but what's with all the vowels other than a?).
At least part of the answer is the Ukrainian Yiddish vowel shift:
The main difference between the Ukraine and the normative Yiddish vowels is as follows:Posted by David Boxenhorn at June 3, 2004 12:06 PM
'a' sometimes becomes 'o': hant -> hont (hand)
'o' becomes 'u': dos -> dus (this)
'u' becomes 'i': du -> di (you)
'e' often becomes 'ey': geven -> geveyn (was)
'ay' often becomes 'a': shraybn -> shrabn (to write)
'o' sometimes becomes 'oy': geborn -> geboyrn (born)
'r' sometimes disappear after a vowel: darf -> daf (need)