Are you unmounting the card correctly before disconnecting the phone from the PC? In Windows you would either right-click the card and click 'eject' or use the 'safely remove hardware' icon from the systray.
Yes ofc but this isn't the problem. I don't know how to acess the file I've put on the card on the phone. All I've done is dragged the video file onto the memory card in the phone but this may be the wrong way to do it. I was jsut trying to find out how its done.
It might have been if you hadn't! Don't mean to offend, just trying to narrow it down.
I just shot a quick video with the phone (stay with me) and it appeared in sdcard/DCIM/100MEDIA. So presumably if you copied a video into the same directory you will then be able to access it via the 'albums' item in the app menu.
Don't forget that supported video formats are MPEG-4, H.263, H.264 and WMV 9.
Did you look under Album (or how it is written in English), it is between the pictures. Just click the video and play. Keep in mind that not all the codex are supported, and .AVI is just the file extension. I play .3GP created with the Nokia PC Suite without problems. I did not try other formats yet.