I am experiencing what appears to be the same issue, and opened a ticket - http://www.openldap.org/its/index.cgi?findid=6831 - because this one did not pop up when I searched for existing ITS's (perhaps my search terms did not match or I just overlooked it). As I mentioned in the ticket I opened, this is not a schema issue - all the schema match on every server, and if that were the problem, none of the users would be served properly. What I found is that the keys that proxycache was looking for did not exist in the bdb it was searching. Why exactly that is, I'm not sure. Hopefully the information I provided in that ITS (or, perhaps some additional debugging information - gdb output or copies of databases exhibiting the problem) will help shed some light. If it is indeed the same issue, I'm all for coalescing the two. I have tested this all the way up through 2.4.23, and there are no commits to pcache.c or back-ldap/search.c since 2.4.23 was released that addresses this problem.