I have this problem on all machines that I every installed (different configurations, different geographical locations, even different OpenSuSe versions) and it's extremely irritating.
When I turn on network manager, all machines simply hang during boot. It seems that they hang on mounting network file systems. This happens even if the machines are connected to wired network (I would understand if it would happen only on WiFi).
Now, this problem disappears if I turn of auto mounting of NFS partitions (each machine mount at least one), by setting the noauto in /etc/fstab.
A solution would be keeping the noauto and leaving the automount to some daemon, that is started later, or fixing the problem with network manager. Any ideas?