Unfortunately, there is little we can do about it, unless freepowerboards change their search system to include old posts.
Think of it that way though: there was a period of about a week/two weeks back in january, when it seemed that all those posts will be lost, because freepowerboards terminated their support v2 version and decided to simply discard all data from forums still using it. So, keeping this in mind, I think we're quite lucky to still have all those 30000 odd posts as an archive which we an refer to: after all, it contains almost 2&1/2 years of SinisterDesign project development and user participation!