it might be very helpful if we would know the version you had before and the version you want to install… Usually FW is corrupt appears when you try to install a G firmware over an A firmware… So… be careful about what FW you want to install and be sure is the right one for your model.
What happened exactly? Maybe you did something wrong… I am still sure that u chose a wrong FW… As far as i know only when the FW you want to update is different from the version of FW you have on phone the update ends with a corrupt update… So… Try to download the 3.5.3 version again… Update… Then try to update again using a higher version. If you get the A version of 3.5.3 try to keep to A version of newer firmware… Keep us to date with your progress…
Hope it helped.