A really old mini SIM card in a really old phone - no signal problems at all.
A new micro SIM card in the above old phone (by putting it back into the mini SIM size plastic surround that you push it out of to make it a micro SIM) - the signal permanently drops after a couple of hours, so you have to turn the phone off and on again.

Basically, imagine in this picture, pushing out the micro SIM and then putting it back into place in the mini SIM size plastic bit that originally surrounded it. So in essence, it's like putting a micro SIM into an adapter to make it a mini SIM, right?
Has anyone else experienced problems when using a micro SIM (whatever way they may have used it - either like the above or in a proper adapter) in an old phone?
It's not like the SIM card is moving. Once I place it into the SIM slot, there is a clip that partially goes over it, thus holding it in place, and then of course the battery goes on top, therefore totally keeping it in place.
One thing though - the micro SIM is from a phone that I dropped, resulting in the screen getting damaged (so quite an impact) - could it somehow have damaged the SIM card?
