I've duplicated that qtopia crash on alpha1.
1) Clear the Z, throught the Okay menu 3,1
2) On boot go through the calibration.
3) I cancelled the personal info boxes, but I doubt that affects it.
4) I put in a CF card, navigated to it, and clicked on an ipk to install. (In this case the qtopia memory applet)
5) After it installs, I correctly eject the CF card.
6) Go to the settings tab, click on network, click on add.
7) I specified my SSID, used 128bit encryption, and left the other settings alone.

Insert CF Network card.
9) Click on connect.
10) Boom! Back to console countdown.
I tried it 4 or 5 times. It didn't happen when I tried installing opera off of the SD card, but every time installing the memory applet off of CF. I'm not sure if it is the program being installed, or something to do with the CF, etc. (I don't think it occurs after just inserting then ejecting the CF flash card - I had to install the applet first.)
But in any case, that 10 steps does it for me every time.