Recently I've found hammer to be deleting my visgroups when I close a map and reopen it. Anybody who uses visgroups extensively will realise how much effort can be put into making useful visgroups, so to have them all deleted every time you close the map is a massive problem. Any objects that were in a hidden visgroup show up in the "check for problems" list so I can reclaim them, but its another annoyance on top of having to rebuild all my visgroups each time. It DOES remember the auto visgroups, but thats not really much consolation.
Another problem related to visgroups is that when I mass select a set of brushes by using the "replace texture" tool (use the "do not replace textures (select brushes)" option), bringing up the object properties box to add them to a visgroup doesn't let me change visgroup properties at all. Combined with the first problem I mentioned, this means adding my clips and hints to unique visgroups each time I load the map involves going round and selecting each one individually - a long and freaking awkward process.
Does anybody else have these problems? I've searched at the snarkpit, VERC and of course google, but there seems to be no mention of them anywhere. Does hammer just not WANT me to be productive?!
I'd saved the original map into a variety of files and it didn't make any difference, but copying and pasting did 