Looking for Answers about samsung MicroSD Memory Card (2GB)?

Hello. My bf has a Samsung Messager II (SCH-R631) and he asked me to add some ring tones to his micro SD card. I previously put some images & ring tones on it like 1 month prior. I had no problems except not every pic I put on the Micro-sd card (the 1st time) showed up. But 80% of them did. Now the 2nd time I went to put a new ring tone on the micro-sd card, I used an adapter (I put the micro-sd card into the regular sized SD card) and inserted it into my card reader. I have an Imac and got the song dragged it to the desktop icon of his micro-sd card. Then I opened the icon and seen the 1 ring tone on it. Then I right clicked and went to eject. No problems. He put it in his cell phone and it said nothing. It did not read the previous ring tones or images that were working from the 1st time, nor did it show the 1 new ring tone I just added. My question is.. If he "does not" turn the phone off to put in or take out the micro-sd card would it or could it erase everything? I only ask that because in my photography classes I did not turn off my camera and I removed my CF card and I put it into card reader and nothing was on it. VERY valuable lesson :( could that also be the problem that happened here? I did see it on the card before I ejected it. He blames me for deleting everything & I hate to say we did not have any of his images/ring tones backed up. What could have caused that to happen? Do you always need to turn off the cell before putting in and taking out the micro-sd card? Thanks in advance!!
P.S. Should I format a micro-sd card before adding it to the phone for the 1st time? & if so, how do you exactly do that on my Imac? Thanks...