Information usually needed to diagnose Subversion problem:

1. Version Control mappings and general settings: (take screenshot)

2. Subversion settings (take screenshot)

3. Module structure (describe or take screenshot)

4. Subversion Working Copies Information (take screenshot)

5. Branches configuration for each working copy (or for those that lead to problems) - (take screenshot)

how to take: in previous tab (Subversion Working Copies Information) press "Configure Branches"

6.  zip and attach <IDEA-HOME>/system/logs directory

how to find:

7. if nothing special in logs, and the problem is related to communication protocol or authentication,