My wife had an Orange UK locked 8900 that was not UMA enabled. No matter what OS was put on there, the preferred network for WIFI/Carrier would not appear.
I spent a few hours on the phone with Orange technical support, fighting the case as customer services didn’t have a clue and wouldn’t forward me to their Blackberry team (for anyone with this issue, talk to the broadband team at Orange, they are also the Blackberry group!). Once I did get through to them, we went through the process again of flashing the phone with the latest Orange OS, just to prove this didn’t unlock the UMA features.
The phone they sent out wasn’t branded, there was no Orange logo appearing during the boot sequence. The replacement handset did and as soon as I turned it on with her SIM in it, joined it to my Wifi network it was on UMA.
There’s no details out there on the web about this that I can find although I did just throw one online at Crackberry. It is a case of some 8900s are UMA crippled and there’s no way to enable it in the interface. They are sent out this way from RIM.
My neighbour is also on Orange UK as is the rest of his house, they have 3 Orange UK 8900 phones. 2 have UMA, 1 does not. It is literally down to whether you have been sent a UMA enabled device or not. Carriers that support UMA generally send out the correct devices. If you are supposed to have UMA and don’t on your phone, just get the unit switched out, there’s nothing you can do with basic tools to enable it.