I am using a laptop with its own web cam. I have two kinects, both set to depth only. When I am ready to record it shows this nag screen. Why? Is it a problem? How doo I avoid getting this pop up?

This means that according to statistics the real frame rate of one or more cameras is lower than selected video mode's frame rate by >= 1 fps. This just signals you have USB bandwidth problems (maybe temporary), and it's not a good time to start recording.
Open statistics panels for cameras and watch when frame rate gets to expected value of 30 fps. If it does not after a dozen seconds, then you should try to do some corrections to your setup, e.g. use other USB port, or disconnect other data consuming USB devices.
If you decide to start recording in spite of low frame rate, than the real frame rate value from statistics will be saved to video file as its frame rate.

I'm getting this issue on a desktop (W8 Pro), with the official drivers installed from the Kinect SDK from Microsoft.

I have one kinect plugged in at the back of my computer, one on front.

There are NO frame rate issues (evaluating background, previews etc), up until the point I decide to start recording. Frame rate might stay at 30 for a few seconds, but it usually just immediately tanks down to single digits while IPI Recorder becomes sluggish.

This happens with a single kinect too, and no matter which partition of my hard drive I record to.

I have no idea what it could be, since it's neither a USB bandwidth bottleneck or an I/O speeds bottleneck... any ideas? (currently uninstalling all kinect drivers and going to try to install whatever package IPI recorder points me to at install, but seeing my luck so far, it'll probably won't do anything haha)

What are your PC specs: CPU, memory etc?
Please provide the trace log from iPi Recorder after having low FPS issue again. To get it, click menu tools > show trace. Save to file and attach here.

Here are my PC specs.





I attached two traces: in the first one, IPI almost froze when the framerate went down, while in the second one, it was "lighter" (only down to ~23fps, no interface lag)

I see from your specs that you have the software RAID enabled. So there is an additional CPU load during disk operations. When iPi Recorder is recording, there are both intensive computations and disk operations. I suppose this kind of combined activity fully drains your CPU power. Though it is strange to have such issues with just 1 Kinect.
To check this assumption, open Task Manager and watch for CPU load while using iPi Recorder.

I saw some traces of PS Eye camera presence in logs you've provided. Please also disconnect it if it is connected to avoid potential USB issues.

There is no spike if the recording doesn't lag (which happens very rarely, like 1 attempt out of 10).

However, when it starts lagging, there is indeed a noticeable spike in CPU use.

I have no idea why software RAID would report as enabled since I only have one hard drive, too...

disconnecting the PS Eye makes no difference

I suppose there should be some driver setting. Look in the drive's and drive controller's properties in the Device Manager.

Nothing in the device manager or driver. Maybe it's just the specs analyzer which got it wrong