[ko williams]"if I drag and drop save the BPAV file onto my desktop am I safe to erase the disk."
Yes, you can drag and drop the BPAV folders from the memory cards to your computer's hard drive but I strongly recommend you don't do that because there's no way of checking the clips if you can't view them. There's also no way to make sure they transferred properly using the drag and drop method.
If you have an Intel-based Mac you can download Sony's Clip Browser Software and it will allow you to view your EX clips without the need for any other software. The Clip Browser will also allow you to transfer your clips properly and will also make sure there are no errors in during the transfer process.
[ko williams]"I am working with final cut pro 5. I need to transfer footage from sony ex-1 card reader. I can view the footage in XDCAM browser but the XDCAM transfer will not recognize the footage. "
XDCAM EX codec is not in your system unless you have FCP 6.0.2 and up. Time to upgrade to next version of Final Cut if you're using EX.
[ko williams]"Question: if I drag and drop save the BPAV file onto my desktop am I safe to erase the disk. "
As Don alludes to, NOT a safe way to copy BPAV
ClipBrowser with CRC enabled.
[ko williams]"I need to shoot more footage with these cards but I am afraid of losing my footage. Help!"
And after copying with ClipBrowser with CRC enabled, make a backup. My recommendation is use high quality "archival" optical disk like Verbatim or Tao Yuden, otherwise two very reliable hard drives or LTO.