SEP 12.1.5 Linux client shows offline in SEPM

I've installed SEPM 12.1.5 on my Windows XP system and "deployed" the client software to 9 RHEL/CentOS Linux systems.  One shows up as offline in SEPM even though the client appears to communicating with SEPM on the Linux side - savtray shows the server info.  Any ideas?  Thanks.