You might want to post on Lithuania's Ancestry board with the VALTAS and BUTKIEWICZ surnames.
Much better to proceed in the place of birth going thru the church records to see if there is a notation that your ancestors were or had gypsy lineage. Do you know where your ancestors were born?
S^KUDERAs in Czech Republic:http://www.kdejsme.cz/prijmeni/%C5%A0kudera/hustota/http://www.kdejsme.cz/prijmeni/No%C5%BE%C3%AD%C5%99/hustota/http://feefhs.org/links/czech.html
distribution of BUTKIEWICZ surname holders in Poland:http://www.moikrewni.pl/mapa/kompletny/butkiewicz.html
map of Poland's wojewodztwoshttp://www.geneteka.genealodzy.pl/