Usually the only time attachments would start going missing was if users were doing strange things in their database or if there were poorly setup permissoins. More recently I have heard many cases of attachments with a size of 0, usually due to files not syncing back to central publishers, files dissapearing, RDBs with sync sets that limit contacts still recieveing too many attachment files or not enough (sometimes a sync fixes it othertimes not). It has resulted in a large number of database rebuilds in an attempt to fix it. This has been mostly apparent since 16.1 but may not be related at all.
Has anyone else been noticing this trend or is this coincidence? Would it be because of more people using new operating systems? Maybe recent SQL patches? Something strange in the ACT software?