[CUSIP No 92833U103 13G Page 2 of 7 1 NAMES OF REPORTING PERSONS Columbia Wanger Asset Management, L.P. 04-3519872 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ ] 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH 5]