some of us like to use bengali scripts while browsing net.windows XP users complained(a lot) that they could not see the begali fonts 'properly' because of very small size.usually this is not a problem for windows 7 users but you guys may also try this guideline.it is mainly for firefox users but the basic holds true for other browsers as well.
after opening firefox,go to Edit>Pref>Content and click to the 'advanced' option beside the 'fonts & colors'
now it'll open another window like this
select "bengali" in "fonts for" box,increase the size according to your requirement and liking and most importantly 'uncheck' the box below stating "Allow pages to choose their own font....".click ok and restart your browser and you should be able to see the bengali fonts normally.
please let me know if this is working for you as well
Gist of the story:size does matter.