Changing the font size in the text style menu while using the slides (default) document class results in odd behavior in Lyx 1.4.4 (and maybe previous versions as well). The normal font size in slides is larger than in normal (say, article) document classes. If no font changes are made, the display font in lyx and the font in pdf output both reflect this. However, if "normal" font size is selected in the text style menu, the lyx display shows a much smaller font typical of the article document class. However, the pdf output shows a font which reflects the normal font size for slides. This descrepancy persists for any of the latex font sizes presented in the text style menu except for the "reset" option, which returns lyx to the default behavior. Lyx acts like it forgets that it is in slides mode when a specific font size is selected.
Dave Raymond Physics Department New Mexico Tech