[CentOS] samba CTDB inability to create smb.conf cache

hi everyone

any experience with ctdb?
I'm setting up a simple cluster, only ldap backend instead 
of tdb2.
One (of the two) server fails this way:

50.samba: ERROR: smb.conf cache create failed

$ ctdb status
Number of nodes:2
pnn:0 10.5.6.32        OK
pnn:1 10.5.6.49        UNHEALTHY (THIS NODE)
Generation:323266562
Size:2
hash:0 lmaster:0
hash:1 lmaster:1
Recovery mode:NORMAL (0)
Recovery master:0

If I copy the file manually while ctdb is running I see:

50.samba: WARNING: smb.conf cache update failed - using old 
cache file
Node became HEALTHY. Ask recovery master 0 to perform ip 
reallocation

and:

$ ctdb status
Number of nodes:2
pnn:0 10.5.6.32        OK
pnn:1 10.5.6.49        OK (THIS NODE)

but only so far as next stop/restart. What the heck?
Why is that one box unable to create that cache file?
Would you care to make some sense out of it for me please?
thx
L.