In all the years I have been using GRPviewer I never tried removing files and then resave the grp file. I wanted to try it today but I can't seem to figure out how to save after deleting the files I wanted removed.
Personally i am using Group Studio by Bishop, it never failed me so far. On another hand, GrpViewer glitched my Group Files and got saved but had alot of inserted data somehow actually missing.