Sencha touch : Inclusion of iframe alongside other controls causes observable lag

hi,

I have added an iframe along with other sencha touch controls such as textbox, button, select, datepicker etc.,

When I started typing in controls I observed a lag and also when I select date using datepicker it is really slow (you can observere this while scrolling years). The page scrolling is also slow comparing with the page when it does not have a iframe

When I remove the iframe the performance is ok.

Can some one please let me know the exact cause for this also appreciate any suggestions.

Thanks,

Naresh