zip-zip hooray!

Well, I've been tinkering with Multi-ADF .zip files, .adf files, .adz files and conversion between them for a while now, and I've noticed something that just struck me as confusing and completely, utterly sick.
I have several games here that I usually keep in .zip files that contain the ADFs in more-or-less logically named form (disk_a.adf through disk_whatever.adf). Just now, I tried unzipping one of those archives and using the ADFs directly - and funny enough, my emulated AmigaOS throws a "Disk Corrupted" message at me.
Okay, I think, maybe something went wrong during unzipping. So I delete the unzipped ADFs and unzip again - same thing.
I try the process with another one of my games - slightly different error message from AmigaOS, but unzipping seems to have broken the ADF here as well.

I start experimenting. At some point, I unpack the ADFs from a zip archive and test them to verify they're "corrupt". I then gzip the ADFs and use the .adf.gz files in WinUAE...
(this is the part where my jaw hit the floor)
... and they work just fine.
I've tried this with several other games where unzipping the multi-disk .zip archives would break the ADF files, and many of them are exhibiting the exact same behavior.

[edit v3] More weirdness. I have by now found at least three disks that will work flawlessly as .adf.gz, but not when I rename them to .adz. When I rename the .adz back to .adf.gz, it works again. [/edit v3]


Now, somebody explain this to me please. I have no idea WHAT is happening here, much less WHY. I mean, zip does use CRC checks to verify that files don't just break like that when handling them... but what the hell is going on here? This one has me completely stumped, and I'm starting to feel like a complete idiot juggling all these files while they just laugh in my face.


[edit] On that note, some of the zipped games don't work at all anymore once I unzip the files. Is there any way I can get to the ADFs again? [/edit]

[edit v2] Also, sorry if I sound a bit like I'm ranting; I'm not. It's just that I absolutely don't understand what's happening there, but I want to know. I really want to. [/edit v2]

Okay, I've resolved the issue of my "broken" disk images now; a few seemed really broken (I couldn't get them to work at all anymore), but most worked after unzipping the .adfs and then gzipping them separately (which is why this whole thing started; I wanted to split my multi-disk archives up again as separate files are indeed easier to handle from within WinUAE).
Still, I haven't got the slightest idea -why- WinUAE, or rather my emulated AmigaOS, behaves so weirdly. Any ideas, anyone? Please?

[edit] Also, I have a feeling this is somehow related to somebody's comment on this board that .adz files "get fucked up easily"... which is why I ask in the first place. [/edit]