Some floppies load photos into MAC ok - some don't.

I have an old MAC (borrowed) OS9.2 and recently got the TEAC external USB Floppy Drive. When I load a floppy, an icon appears on the desktop that holds the photos from the floppy. I then copy those, edit and I'm in business. Sometimes, I insert a floppy (2HD IBM 1.44MB) and nothing loads to the MAC. No icon... just beeps that stop after awhile and then nothing.
I have the same floppies - they are Imation brand. I insert them into my digital camera, reformat them, take pictures and do the cycle again.

Is this a drive problem or a floppy problem? Have search the net, and can't seem to find the answer I need. Thanks.