[lou2of2]

I'm sure closing OF using the Home button during synching with MobileMe will interupt the sync, but what about locking your iPhone with the button on top (leaving OF open)?

[whpalmer4]

That shouldn't interrupt the sync, but it has been discovered that it will cause the data connection to switch from WiFi to cellular after about 30 seconds, which might slow the sync down quite a bit.

[tmilovan]

My connection breaks every time when iPhone auto-lock himself. So, I have to either turn off auto-locking, or constantly fiddle with iPhone when I have big database to synchronize in order not to have to start all over again. I that expected behaviour?

[whpalmer4]

If you download the latest iPhone OmniFocus version (1.6) you may find your syncs are fast enough that this is no longer an issue.

[tmilovan]

I have it. And it is fast enough unless I forgot to sync the database for more then a week. If I do forget, the next time I sync the database it lasts for couple of minutes and that is when I encounter described problem.

[whpalmer4]

You don't launch OmniFocus for more than a week on your iPhone? Or do you have auto-sync turned off?

Are you making your sync connections via EDGE, 3G, or WiFi? Which generation iPhone do you have? How big is your database? I can imagine that when you do a sync of the prodigal iPhone after a week or so of activity, it tries to compact the database (which requires writing the whole thing back to the server) and if you've got a slow cellular data connection (as suggested by the discovery mentioned above) and a lot of data to write and a slow server you might end up getting a timeout of some sort.

I know there isn't any intention for the sync to fail, and would suggest you contact the support ninjas if this problem continues with 1.6. Or you could add a repeating action reminding yourself to sync every couple of days...

[Brian]

The 1.6 update should make things faster, even if it's been a while since the iPhone app synced. Since it hasn't been released for a week yet, I'm not sure we can say exactly how much improvement tmilovan will see in his worst case scenario. I look forward to more data, though. :-)

As to what's specifically going on here, I can't be sure, but this sounds similar to what was happening with another customer recently.

While working with him, we discovered that a recent iPhone OS update introduced a change: the phone will stop using the WiFi connection when it goes to sleep. We presume that Apple coded this up in order to try and preserve battery life.

Unfortunately, it means that a sync that's in progress at that point will switch over to the slower cell phone network. Best case scenario, that means the sync is going to take longer to complete than it would over WiFi. Further, if there's a delay in establishing a connection to the sync server over the new network, the sync may time out entirely.

It's possible that's what you're seeing happen. This isn't really intended behavior - it's a consequence of a change that occurred in the OS that OmniFocus runs on top of.

We aren't aware of a way to work around this change in the OS, but I know we have a change request open on increasing the amount of time that OmniFocus will pause a sync before giving up on it. I'll make a note of this thread in that change request, so the team knows it would help you, as well.

[Brian]

Whoops, forgot two details I wanted to mention!

From what we've observed, the timer that causes the network to switch is not related to the auto-lock setting; instead, the OS forces the switch to happen 30 seconds after the last touch on the screen. This is why fiddling with the phone helps: it prevents that timer from firing. The phone not sleeping is a side effect.

The other thing I wanted to mention: the customer that helped us figure out what was going on had an iPhone 3GS, but because he wanted to preserve his battery life, he had the 3G network turned off. This means that the sync was dropping all the way down to the EDGE network after that 30 second mark was reached.

He was able to partially solve the problem by leaving the 3G radio enabled; the sync still dropped down to the slower connection, but it was the faster of the two slower options. Thought I'd mention that just in case Tmilovan was running in a similar configuration.