With Half-Sized Frame and SP/LP error, am I getting lower quality?

Seven years ago, I recorded some videos with my Canon ZR miniDV camcorder. I want to preserve the quality of these videos by archiving them on my Mac. The read head on this camcorder is broken. So, I'm borrowing my brother's Sony Digital Handycam DCR-PC110 NTSC to play these miniDV video tapes.

When I use iMovie 6 to import, I get this message:

"The camera is sending half-sized frames, which iMovie can’t accept. Check your camera’s record mode (this is the setting that affects recording quality, which determines the total recording time on a tape). The mode must be set to “SP” or “LP.” If that doesn't help, try removing all the cables and batteries from the camera, wait a minute, replace them, and then reset the date, time, and record mode."

The recording mode is already set to "SP". However, I still cannot import. Every time I try to play the video, it shows a fraction of a second of the video and then it stops. If I disconnect the camera from the Mac, I can play the video without a problem. It seems that iMovie 6 will not allow me to play this video.

Does anybody know what the problem is?

With my brother's miniDV tapes, I don't get this problem on his Sony Digital Handycam.

From some research, I read that it might have something to do with playing a PAL recording instead of NTSC. However, my cameras are NTSC. I've never (consciously or remember to) use PAL. iMovie 6 is set to 29.97 bps frame rate, which is supposedly NTSC.

I tried the suggestion from this posting:

https://discussions.apple.com/thread/379223

Which is:

- I disconnected the camera from the Mac.

- Started up iMovie 6.

- Started playing my miniDV tape.

- Connected the firewire from the camera to the Mac

Now, I can play and import the miniDV video on iMovie 6. However, I'm curious as to whether iMovie is inputting NTSC and saving into PAL, or vice versa. Therefore, I'm concerned about the possibility of losing quality. Would anybody know if I will be losing quality?