Features suppressed after closing and re-opening a file

Folks,

We have this happening occasionally, cannot find any real rhyme or reason, and has happened in various versions so just a general "have you had this happen" type question.

So, once in awhile I will have a user (different each time including myself) where we make changes to a file, save it, close out of SolidWorks and then next day when we reopen the file features are suppressed that we did not suppress.

Have you ever had this happen, ever find a reason?

Thanks,

Brian

SolidworksParts And Features