I have unchecked "Show Solo" so Cell does not show while I am not in a group and this setting does not last. Every time I log in Cell is showing while I am not in a group.

Edit: this also happens when dropping groups from instances.

I'm having the exact opposite issue myself. I'm trying to set cell up for all my DPS since I've tried it on my healers and I love it's features. However the only DPS spec it won't uncheck the show solo and or the show party options for is my Aug Evoker. Can't find any option that would be forcing this to be changed but something in my profile is causing this cause if I reset all my settings it stays selected on reload just fine. If anyone knows what option I have selected that's causing this I would greatly appreciate a response so I can go in and change it.

If it helps I'm specifically trying to set it up on my mage but I've also tried this on my DK so I can easily combat res and it won't stay on either spec.