Some modules over-write CORE files - and when they do, the author of the module will usually tell you which CORE files are affected. When you UPGRADE, the CORE file into which the relevant module has its code located, is again over-written by the new version's corresponding file - thereby taking out whatever edits were made.

When you see CONSTANTS (eg: TEXT_PAYPAL_VERIFIED_SELLER) it means that the define for that constant (usually in a named language file) cannot be found - so the system just returns the CONSTANT.

You can usually work this out by looking at the additions that were made to the site (in your case, add-on sideboxes), and taking a look at the files relating to that add-on. (Download the addons in question again, if they are not on your home computer - unzip them, and see what folders and files are being used. Then - using your FTP program, COMPARE the contents of your server folders with those in the add-on's folders. The two systems must match as far as folders and files are concerned. In any case where a CORE file is involved, you should rather do a FILE COMPARE using winmerge, and then "copy across" relevant code from the add-on file, into the core file. This prevents blanket overwriting.)

These procedures are necessarily MANUAL... you should NOT use cranky "instant update" programettes to do these tasks.