Next time I get access to the camera I'll replace the microSD card with one tested for class 10 performance and see if that helps.
The video is currently recording to the card just fine as it plays back okay when I remove the card from the camera, so I would have thought a simple file transfer from the camera should not cause it to lock up and become unresponsive until power cycled.
I have an 8GB card class4 in mine to record on motion detection.
I do have troubles from my (2008) laptop changing settings on the 5222L with everything wired in Google Chrome.
My desktop (2006) works a lot better with IE8 on win xp.
Anyways, I turned on 24x7 sd recording, and was able to have 4 downloads (2 on laptop, 2 on desktop) + recording 24x7 enabled, and no time outs.
Now c4 on 8gb isn't necessarily the same as on a 32gb c4 from my understanding.
Hopefully, you can provide more information about your network, computer power, etc...
I do get faster downloads on the 2230 with 32gb class 10 than the 5222L with 8gb c4.