Small font problem in Bangla

I am using Avro 5.1.0 for writing Bangla. Everything was ok until Yesterday i installed .NET Framework 2.0 in my Windows XP (sp2). And after installing it, my Bangla font become too small.
I have uninstalled the .NET Framework, reinstalled the Avro.
But there is no change .
What should i do now?
(here is a screenshot that shows the problem on my Internet browser)

