I have a Sony Ericsson Xperia Pro (MK16i) on Vodafone prepay. It is running Android 2.3.4 (gingerbread), updated with any Play Store updates (I can't specifically remember if there have been any, but the "software update" option says the phone is up to date), but otherwise stock - not rooted and the bootloader is still locked.

For about the fourth or fifth time this year, I am not receiving text messages. If past history is anything to go by, I will need to wait 3 or 4 days and then the backlog will clear all at once. I have tried (both previously and this particular time):

- turning the phone off and on
- pulling the battery while off
- pulling the battery while on
- deleting all text messages on the phone
- sending a text message to myself
- sending a balance request to 777
- putting the sim card in another phone (an iPhone)

With the exception of the last one (the sim card in another phone), none of these things has ever made any noticeable difference. Putting the sim card in another phone worked once many months ago (all text messages were received on that other phone), but has not worked since. I have just tried this again with no joy.

I can send text messages fine (they are definitely received), and voice and data work as normal. This seems to be all networks, but all my usual contacts are on Vodafone so it may be that texts from another network could have been received on at least some occasions, but I'm not sure about this.

I have tried calling Vodafone previously who suggested some or all of the previous steps and I am not sure I can face it again.

I am aware that this is a common topic on both Geekzone and the Vodafone forums, and I have (hopefully) tried all the obvious suggestions. The one major suggestion I haven't tried is updating the firmware on the phone. Sony has published an Android 4.0 (ICS) update for my phone, but the reception to that update seems to have been mixed (things like slowdown and changing the QWERTY keyboard to AZERTY seem to be frequent comments), so I'm reluctant to do this if I don't really have to. I'm also pretty happy with the phone as it is - performance is really snappy for the things I use it for (I don't use it for games, and only the odd app doesn't run on gingerbread).

Is an Android update something that is likely to fix my text messaging problems? My instinct is that it won't, as putting the sim card in a non-Android phone doesn't seem to do anything (though the one exception is making me doubt myself). 

Thanks in advance for any thoughts.