Client expects response to change-password extended operation

I noted some old correspondence about this topic in the mailing-list archives, but now it has bitten me.

We have an email server in my shop (from Mirapoint) which offers users an option to change their password. It sends the password-modify extended operation, but the user's session hangs, apparently unless Mirapoint gets a response.

I understand that this is non-standard behavior. But unfortunately I'm stuck with this not-very-satisfactory product. Is there any way I can tweak openLDAP to respond to the password-modify ex-op?