10.10.2 Combo Update silently updated today, and now works over 10.10.1.
thanks for the update
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I believe with Yosemite, when you try to do an erase and install (with a USB stick, with 10.10) it forces the machine to go to the most recent version of Yosemite unfortunately. If you watch the steps of installation, the first thing it does is 'download additional components' before installing anything. Tried this the other day when we had to wipe a co-workers laptop, and used our OS X 10.10 USB stick. It required an internet connection for us to install OS X. I am not sure if this is what you were referring to, but I found this very odd.
It's not really what I was referring to, but that is interesting (and somewhat annoying) so thanks for sharing all the same.
I was referring to an in place update on an already running Yosemite machine, where we had 10.10.1 installed, if I manually downloaded the combo update installer for 10.10.2 that update would update machines running 10.10.0, but would not allow 10.10.1 machines to update to 10.010.2 using that installer. (hopefully that isn't to confusing)
Other users have said that Apple has since fixed the Combo update that you can download from their to work as expected.