I have exactly the same problem. I contacted my network because I thought I had a network issue. They asked me to remove the sim card and try it in another phone to check if the problem was with the phone or the sim. (It wasn't the sim or network problems).
However, due to the design of the mini pro you have to remove the battery to get to the sim, which caused the date/time reset. (With my old S-E phones you could leave the battery in.) So I guess this is a design fault as well as a software fault. When I put my sim in my old S-E phone, the date/time updated automatically from the network, so I know it is a problem with the mini pro only and not a problem with the network.
I am due to send my phone back to 02 under warranty to fix this, but as I don't really want to be without my phone for a fortnight, could you please tell me how to fix it instead?
