Bixolon SRP-350 cyrillic printing

Hi,

i've downloaded srp350 driver from bixolon.com and there were sample applications. Just opened c# project and tried english and 'õüäö' letters worked ok for me, but when i try to print something in russian as a result i always get question marks =/

if anyone knows how to make it working i would be very thankful ^_^

Thank You in advance !