Matlab vision textInserter Linux invalid font

Hi,

I'm using Matlab in Ubuntu 12.04. I have a problem on using vision.TextInserter function of vision toolbox. I can only use the font LucidaSansRegular whereas if I try to use a different font I receive "Times is not a valid setting for the Font property". I have tried all the fonts returned by the command listfonts. My basic code is the following:

if true
  h = vision.TextInserter();
  h.Font = fontname;
end

It seems that the only available font is LucidaSansRegular. Why? Thank you