I've logged this problem with vodafone and they have been calling me every day (at least) to try to solve it. They have "escalated" the problem beyond the entry level help desk, which is good news. I suspect it's a combination of a network problem and a design flaw in the iPhone 3G and 3GS. Download speeds lock in at around 115-117 kbps if the phone is taken into an area of low 3G signal strength, where the phone still indicates 3G service, but not into an area where the service downgrades completely to 2G. Taking the phone back into the high signal strength 3G area results in download speeds remaining at 115-117 kbps. Higher 3G speeds can be regained by one of three methods: 1) switching the 3G service off and back on again, 2) switching to airplane mode and back again, or 3) powering down the phone and powering back up again. Note that merely turning off the screen using the button at the top of the phone achieves nothing.

A co-worker of mine has the same problem on his iPhone 3GS. We did a comparison test in the same room at the same time using the SpeedTest.net application.

My last experiment today was to insert my SIM card into a 3GS phone at a vodafone store. Unfortunately the problem was not replicated, most likely as the phone would have to disconnect from the vodafone network and then re-establish a connection, thus effectively repeating step 1 as stated above.

How to fix this problem? Good question. Maybe the upcoming 3.1 OS update will be the solution. Maybe...

Tomorrow's experiment: I'll try to connect to the only tower I know that is HSUPA in Dunedin and report back. Not sure if the iPhone will connect to HSUPA though. Most 3G towers are HSDPA in Dunedin, I believe, but I am open to correction.

One other (off topic, admittedly) issue: I noticed that my 3GS was decidedly yellow in colour compared to a 3G iPhone. The vodafone representative reported that he'd seen one 3GS phone screen that was beyond yellow, and had turned brown. Factory recall, anyone?

David Everett