Every time I open my MacBook, I am immediately greeted with the Sync Failed warning icon in the top right corner.
This is because OmniFocus tries to sync right when the machine wakes up. Apple’d DHCP and network config is fast, but not that fast.
My suggestion is that OmniFocus should really wait a little longer or inspect if the network connection is actually available before it attempts to sync. It will save people a click and make Sync-after-wake more robust in general.