Call waiting / Not getting calls?

[Moogle]

I don't appear to have call waiting in operation.

But, more than that - I seem to have an issue where, if I'm doing something on the internet (e.g. checking email), the call doesn't come through. Take, for example, a mild incident today:

Meeting my beloved mother, for once in her life she's remembered not only to have her phone, but to have it on (will miracles never cease!). I call to find out where she is. She's 5 mins away.
So - while waiting for her, I go into my gmail to respond to a mail. Mother arrives - 'I tried calling to say go queue for a coffee, so we didn't have to wait, but it went straight to voicemail'.

I hadn't moved, reception was still good. BOO HISS ETC.
What's going on?

 

[jason-567]

if your using a GPRS connection to check emails i dont think that you will be able to recive voice calls, i might be mistaken but i know on old phones that was the case. but i have a call waiting problem too when i have 2 calls running at the same time and one hangs up when trying to switch back to the other call the screen keeps locking itself making it impossible to switch to the call

 

[Moogle]

hmm... how do I know if it's GPRS? I think I'm on... whatever 'H' is.
Is there any way to stop it using GPRS, if that's the problem (but still enable it to use the mobile network for syncing, etc)?

 

[SUroot]

Gprs is the mobile data connection. If youre connected via gprs, its because that is the best available at the time. It's the worst of all mobile data connections, if you turn mobile data off when it says G, you will get calls. If you leave it on, you wont receive calls if data is being used.

List of mobile data connections on the desire, oldest technology / lowest speed in order.

G GPRS
E Edge
3g 3g
H HSDPA

 

[Moogle]

hmm - I'm fairly certain most of the time on I'm 'H'. *sigh*

I'll make a note next time it happens.