Traveler 9 replies on iOS

When replying email from an Apple device with Lotus Notes Traveler, we have the following

“User /O” does not appear to be a valid email address. Do you want to send it anyway?

Sending the mail works.

IBM says it is a warning that can be ignored ( as per technote http://www-01.ibm.com/support/docview.wss?uid=swg21441053 http://www-01.ibm.com/support/docview.wss?uid=swg21441053 )

Strange thing is that on my own device ( an iPhone ), I have two accounts created, one for my company and one for my customer.

The one configured for my customer is accessing a traveler 9 server and the another one for my company is accessing a traveler 8.5.3 server.

With my company account, i have no warnings while replying neither that problems when sending new mails. I only have problems with my customer account.

I have a PMR open @IBM but nothing found yet.

Does anyone know how to solve that strnage behaviour ?

Thanks for any help

Christophe