I am unable to confirm this.

What release of joomla are you using? What extensions do you have installed?

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/5221.

Hi Brian,
I use the latest version of Joomla (3.3.6) and I think that the problem is from the core of Joomla (profile.php in models of com_users), not from an extension

I work with the lastest staging branch and can also not reproduce this behaviour.

I have the same problem (joomla 3.3.6 version), i had install jomsocial. but them said that is a issue from joomla core. Please help me i lost the super user group permission.

viewed the answer from jomsocial:
**
Yes, it's Joomla! issue. Users lost assignment to groups.
We reported this issue and fix is on the way.**

http://www.jomsocial.com/forum/technical-issues/22018-the-user-admin-and-registered-lost-credentials-at-any-time-assigned-user

all component are licenced

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/5221.

As the only people who have confirmed this are jomsocial users we have to conclude it is an issue with jomsocial. I am closing this at this time. If more information is provided to show that the issue is in the core of joomla it can always be reopened

You might want to consider actually fixing this Brian.

http://issues.joomla.org/tracker/joomla-cms/5138
http://issues.joomla.org/tracker/joomla-cms/5144

Closing this report is good, because it is a duplicate, but that doesn't mean issue is resolved.
http://s15.postimg.org/vqngj1fwr/Screenshot_2015_01_05_20_14_34.png

This problem occurs dominantly with JomSocial, because JomSocial saves a User basically on every use of the CUser object, even if there was no change. So you have a huge load on the database very quickly and it seems the statements simply get dropped. In a MySQL bin log I had the update on #__user, the deleting of the group 3 seconds later and the insert statement for the group missing completly.

I'm also seeing this now as I'm using Easy Profile. I have group specific menu items and started to notice when changes were made the menus would disappear. This is on Joomla 3.4.1.

In my case it was Joomla 3.3.3, but I assume this can happen on any version where groups are saved this way, at least back to 2.5 .
How about comparing database with user object and only change it, if there is a difference. That should be at least as save as the current solution. However I think the components using the User class should be more responsible with saving. Maybe core Joomla should offer a way of saving only the data for the #__user table, since a lot of 3rd part components need to use it.