LDAP LTM authentication

I am trying to integrate our F5 LTMs to authenticate to ADS. We use spaces in the usernames. This works just fine with Web console access but when trying to access via SSH, I get this wierd message, 'Cannot load user credentials for user "xxxx xxxxx" '. At the same time, this works just fine with the VE version of LTM but on a physical box it doesnt. Has anyone got this error or anyone who has implemented it. I opened a case with F5 and they say that space in username is not supported for SSH. Looking for options and experience.