big problem with sql replication 2008 and cannot enable weblog

Hi.

I've got a big error , as soon as i want to sync a new subscriber, the first time it's really ok (15 min to dw the db and the data). Very well. But if i just try to sync this subscriber just after, i've got an infinitive loop and the error message on my client is ;

16:10:26:Synchro Error:Microsoft.SqlServer.Replication.ComErrorException (0x80004005): The Merge Agent received the following error status and message from the Internet Information Services (IIS) server during Web synchronization: [404 :'Not Found']. When troubleshooting, ensure that the Web synchronization settings for the subscription are correct, and increase the internet timeout setting at the Subscriber and the connection timeout at the Web server.
   at Microsoft.SqlServer.Replication.MergeSynchronizationAgent.Run()
   at Microsoft.SqlServer.Replication.MergeSynchronizationAgent.Synchronize()
   at Odyssee.Desktop.WebSynchro.Synchro()
16:10:24:0%,Status:InProgress,Message:The processing of the response message failed.
16:10:24:0%,Status:InProgress,Message:The Merge Agent received the following error status and message from the Internet Information Services (IIS) server during Web synchronization: [404 :'Not Found']. When troubleshooting, ensure that the Web synchronization settings for the subscription are correct, and increase the internet timeout setting at the Subscriber and the connection timeout at the Web server.
16:10:24:0%,Status:InProgress,Message:The Merge Agent received the following error status and message from the Internet Information Services (IIS) server during Web synchronization: [404 :'Not Found']. When troubleshooting, ensure that the Web synchronization settings for the subscription are correct, and increase the internet timeout setting at the Subscriber and the connection timeout at the Web server.
16:10:24:0%,Status:InProgress,Message:The request message was sent to 'https://xxx/SQLReplication/replisapi.dll'

I want to enable the Log on the server than host the replisapi.dll but it doesn't work and i don't know why

ON regedit on HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100\Replication
I put WebSyncLoggingOff to 0, WebSyncLogSeverity to 1, WebSyncNumberOfLogFiles to 2 WebSyncLogFileSize to     
1,000,000

Then i restart IIS and replisapi.dll?diag don't confirm me log is enabled
ReplIsapi Settings:

Property Value
REPLISAPI version (replisapi.dll) 2009.100.1600.1
SNAC version (sqlncli.dll) 2007.100.1600.22
Logging Enabled FALSE

This is a win 2008 R2 standard 64 bits

PLS help me :(