Font Size & Face setting reset on save in Page Menu Bar options

I am new to html, new to WP, and new to BFA, so thanks for indulgence if this is a stupid question.

When I change the Font Size & Face setting in the Page Menu Bar options to:

14px "comic sans ms", arial, sans-serif

and save it, the only thing saved is:

14 px

but the font change does take effect. But if I resave the options page again, I lose my font settings, and only get the 14px.

Any ideas?

Thanks.