Nokia :: 5800 Xpress Music - Reformatted Memory Card / Cannot Click Download Button On Applications In Ovi

I've recently had to reformat my memory card as the camera refused to work with the memory card inserted. I took off all pics, videos and music and saved them to the computer. However, when I've gone back to the Ovi store and into the "my stuff" tab, I cannot click the download button on many of the apps (mainly the ones that I actually use which makes it even more annoying). My husband has told me to go into "settings", then "application manager", then finally into "installed apps" and delete the files for the apps that I would like to reinstall (to reactivate the download button again). fantastic idea, but the file names don't give me any sort of clue as to what app they're for. I asked if it would be quicker and easier just to delete everything from the "installed apps" folder, at which point my husband nearly had a breakdown and told me not to do that as there were files in that folder that relate to firmware downloads and could cause more problems by deleting them.