Well good we now can write off whether you know that the switch has to be in the on postion to make your computer work, but did you check to make sure the computer was plugged in? Since as you said "I don't have much, if any, experience working on firearms," I presume you know what happens when you assume anything. Now that we have gotten the computer isn't the problem part out of the way perhaps we can move on to your pistol.
First off referring to your statement "I don't have much, if any, experience working on firearms" Rodolfo Fierro
answered the question with advice he presumed (notice I didn't say assume) would benefit you and was perfectly good advice to be quite frank. Let me repeat what he said "You should be able to press the floor plate of the magazine down WITHOUT the magazine moving. The magazine should not move at all without pressing the mag. release."
I don't see anywhere in your post that you even tried doing what he said. And without that info we can't suggest if you can fix it or if CZ-USA should look at it. One question not asked or answered was/is does this happen with Both magazines or only one of them? If it's only doing it with the one mag then you have a mag issue which may or may not be fixable. If it happens with both mags then you have an issue with the mag catch, and frankly your saying you have to hold the bottom of the mag up when the slide operates to make the pistol work properly, then I would have a reasonable expectation that the pistol needs work, But until you and or we know if you have the trouble with both mags then that's a guess on anyone part.
To be completely honest with you, frankly I am stunned you haven't been on the phone with CZ-USA and talking to them as soon as you got home if not sooner. You are taking your life in your hands by operating a weapon without taking to the professionals that get paid to know or think is wrong with your pistol an deal with it. What you are describing it tantamount to a wheel gun cylinder only rotating 90 persent of the way and then taking a chance the round will actually go through the barrel and not explode in your face.
I have no doubt you are going to be offended by this post and think all sorts of nasty things about us. Frankly I do not care. This is the Christmas or Holiday Season and your copping an attitude towards the man that at least tried to help you and you apparently seem to have ignored at least partly is not in the spirit of life in general an certainly not at this time of year. No one gets paid here, This is a private forum and not subsidized by ANY company at all. I take a great deal of pride in my members and the fact that they are willing to help anyone that asks for it, and in the process knowing they can come here with their own questions and not get bombarded by banners, ads and sponsorships.
To help you out I would like to mention another CZ forum that may be able to read your mind and help you, the URL is www.firearms.us
and good luck trying to get past their double secret password question to join.
Oh ya and just to show you I actually bear you no ill will and in the Spirit of the Holidays here is a list of sites I found that had CZ 97B Magazines, and or did at the time I posted them. http://www.gunclips.net/cz97gunma.htmlhttp://www.gunsamerica.com/937560999/Non-Guns/Magazines-Clips/Pistol-Magazines/Other/CZ_Mag_97B.htmhttp://www.bing.com/shopping/search?q=cz+97b+magazine&qpvt=cz+97b+magazine&FORM=HURE#x0y0
Oh and you had best buy the mags soon because I have a CZ 97B custom made that cost more than yours did twice over and I am was looking fo rmags myself, But I am letting you have first pick.
There you go, and before you bad mouth us know that I am Jewish and by trying to help you after you insulted one of our members is a perfect example of turning the other cheek, and I have been more "Christian" to you than you have been to Rodolfo Fierro you may have forgotten just what this season is about but we haven't. Peace out and Merry Christmas and Happy Hanukkah.