MWI doesn't see when voicemail is deleted


I have 2 servers with asterisk same version (1.2.13), on gentoo.

On one of them only, I have a problem (recent), and I can’t find why.

When a extension has a voicemail in box, it correctly receives the MWI.

But, when I delete this voicemail by ARI, the message is physicaly deleted, but the MWI is never light off.
And, the manager command MailboxCount doesn’t neither give the right number.
It seems asterisk doesn’t see the msg deleted on this server.
What and where can be the difference between them please ?

Thank you for your help.

PS : sorry for my bad english