Same answer applies: contact Omni support directly and they will help you out or get you a refund.

If Apple has done its part of the work correctly, there should be no way any requests OmniFocus makes of the network stack should disrupt your network connection, any more than sending packages should cause UPS trucks to crash. There are thousands of people syncing OmniFocus in the same manner you are trying to do without trouble. There is also a large number of ways in which a network can fail mysteriously in a manner that is very difficult to understand without considerably more visibility of the situation than we have here. There's a reason why so many networking gurus have gray hair :-)

One of the developers here just noticed that another iOS app fixed a bug "which could cause wifi connections to drop when bluetooth is enabled".

On the off chance their bug is related to what's being reported here, can the folks that have encountered this let us know if they have both WiFi and Bluetooth enabled? If they do have both enabled, does disabling Bluetooth temporarily resolve the issue?

Oh look at the post immediately above mine. <sarcasm>I am smart.</sarcasm> :-)

JustSomeGuyYouKnow, can you let us know if Bluetooth is enabled on the device(s) you're having this trouble with?

We've gotten some info from another developer that appears to explain what's going on here. Bonjour actually tries to find your sync server using both the WiFi and Bluetooth radios. That traffic, combined with the sync traffic, can cause radio interference.

We've got a lead on a way to work around this, but for the time being, folks experiencing this should be able to work around the issue by turning Bluetooth off for the duration of their sync. Sorry for the inconvenience this causes!

turning off BT has solved the sync issue for me! (iPhone4).