Unfortunately that means using GPRS, when I occasionally need it, is a very cumbersome process of having to install and then remove the settings each time.
I tried the 'Manila Dial-up enable/disabler' mentioned in another thread, but I find that this, rather than correcting the problem, just duplicates the 'wrecking bar solution' in that with it activated I can't turn GPRS Data on at all. If I deactivate dialup disabler, then as you might expect Data turns on unprompted at the next phone-home incident. Surprisingly though, and rather uselessly, when I reactivate the dialup disabler it doesn't turn Data off! So although well-intentioned this is a rather broken solution. It doesn't achieve the requirement, which is:
Data switch on: GPRS activated.
Data switch off: GPRS deactivated.
I say to myself, SUUURELY there has to be a better answer to this? The situation is a bit like going back to the 90's with analog modems dialling unprompted and racking-up a huge bill. Seems OS programmers never learn from previous design blunders.