Can SIM be safely swapped with power on?

[caravanboy]

Hi,
I have a UCM/GSM4 3G model.  I need to experiment with a SIM from a different provider. Is it safe to remove and re-insert a SIM whilst Comfort is powered-up or do I need to power down?

[slychiu]

I beleive it is not recommended, but we often swap SIM cards without powering down! And we have not had any problems