Three PAYG SIM not recognised?

[mossywell]

Anyone tried this? My Excalibur is SIM unlocked and works with a selection of non-3 SIMs, but using a PAYG SIM from 3 says SIM not found (or words to that effect). But, the 3 PAYG SIM works fine in my Nokia N95. I notice that the SIM pinout is different (3 has only 6, but Vodafone and tmobile have 8). I confess I didn't realise that there were still 2 types on SIM in circulation 'cos I thought that all SIMs would work in all mobiles (assuming they're unlocked and all that) these days? I am I just being naive?

[indiekiduk]

Yeh I believe the 3 SIM is for 3G phones only. Whereas the other carriers' sims work in 2G and 3G phones.

When there are no 3G cells in range a 3 phone is supposed to revert to T-mobile's 2G network however I guess they decided to prevent 2G phones doing this as it could get expensive for them if too many customers are using the out-sourced network perhaps.

[mossywell]

Cheers for the reply. I since also tried it in an unlocked N73 (a phone that 3 sell or used to anyway) and that can't see the SIM either. So, I reckon it's time to call 3 and tell them I have a dud!

The think that gets me is that the SIM is a different layout to all those I've seen before, but the SIM-only deal says "if you want to keep your existing phone, get a SIM-onloy deal and provided the phone is unlocked, you're good to go" (or words to that effect). Hmmm... I'm not so sure.

One final question: I've hunted around for SIM specs but all I can find is a Russian site giving the PIN layouts of a couple of SIMs. But, can someone point me to a site that lists what kind of SIM (pin layout) is used with which kinds of phone?

EDIT:
Ahh - I thought I was getting one of these:
http://en.wikipedia.org/wiki/USIM
but I actually got one of these:
http://en.wikipedia.org/wiki/RUIM