Users/Groups page loading so long

Hi, there are tens of thousands of users in our ldap. When I click to Users/Groups page, it can take minutes to finish. Sometimes I just need to modify groups settings. Can this time gap be somehow reduced?

Hi, today I’'ve upgraded to 3.0.0 version. Logged in, click on Users/Groups and still it took about 20 seconds to open the page. It shows there are 3,679 users in my LDAP. This would be acceptable, but problem is it takes sometimes few minutes to complete, and sometimes it never finishes.

This would not be such a big problem, but I maintain Groups manually and every time I make changes to groups it behaves the same. Sometimes, this is breaking the groups in users rosters (users are disapearing/are offline even the are online). Any advice what can be wrong?