Windows SharePoint Services - Browse User Information/Check In Security Issue

We have a top level team site setup with 5 team subsites, each of the subsites is restricted to a certain company. All companies have read only access to the top level team site. We don't want each of the users in the 5 companies to have access to the People and Groups links within the team site (no suggestions around hiding or removing please). We removed this access by creating our own security level and unchecking 'Browse User Information'. This does as it says on the tin and restricts access to the people and groups link. But we now get a 'Access Denied' when trying to check documents in 开发者_如何学Goto the shared documents library within each team site and it asks the user to request permission!

If we put the 'Browse User Information' check back on we can check in again, but we expose all the people and groups information!! BIG ISSUE!

I can't find any information on this on www.google.com and I cannot believe someone hasn't seen this issue before.

Any help greatly appreciated.

If you want to prevent people from one company to see the members of another company, you can just edit the group settings and set the "Who can view the membership of the group?" setting to "Group members".