Hi Ashwin,
Even I faced similar issue, So I corrected the value of ~ITSMOBILEELEMFACTOR and ~ITSMOBILEELEMUNITS parameters in GUI Configuration to a certain value so that the display is alright for different browsers. This OSS note might be useful for you 1316326 - ITSmobile: HTML element size is independent of font size
Again, If you are using ~ITSMOBILEELEMFACTOR and ~ITSMOBILEELEMUNITS parameters then you might have to remove the ~POPUPS service parameter from the GUI Configurations.
Cheers,
Avinash