System.FormatException on Mobile Application

[Sachin K]

Hi,

I have developed a mobile application using asp.net. The
application works fine on Nokia 7210, Openwave emulator
and Microsoft Mobile Explorer but when I deployed the
application and try to access the same from a nokia 6610
and nokia 7650 handsets, upon loging into the site and
after display of the home page when I click on any of the
links I constantly get the following error.

Error:
Server Error in / System.FormatException for a Base-64
Char Array

Can any one suggest solution to the problem

Thanks,
Sachin