Forms authetication Sample UILogon failed


I have problems trying implementing custom authentication form to access my report, i did all steps mentioned in form authentication sample, access to /reportserver by Logon.aspx works, while access to report manager /Reports by UILogon.aspx fails with this error:
"Authorization ticket not received by LogonUserreportServer: lyittma001vw instance: RS_LYNCMONITORING url:http://lyittma001vw/ReportServer/ReportService2010.asmx "
Could you suggest me something? thank you
My product version is:
Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (X64) Apr 2 2010 15:48:46 Copyright (c) Microsoft Corporation Standard Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1)