I have just read that other thread, and I'm not a great deal wiser! But I think it must be a setting specific to your phone, and possibly to the version of Android.
You could try browsing the device guide to your phone on http://support.vodafone.co.uk/Device-Guides/ to see if you can find any clues. Alternatively you could post your question in the relevant section of http://forum.vodafone.co.uk/t5/Devices/ct-p/7 giving details of your phone and the circumstances which trigger the message, and see if someone familiar with that phone can offer any advice.
