Having success so far with following setup...
My Setup
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MacBook Pro (15" Mid 2010) with 4gb RAM
Mac OS X 10.9 Mavericks
VirtualBox 4.3.6 (Free from Oracle!)
Windows 7 Pro
Allocated 2gb RAM for OS X and 2gb RAM for Windows 7
Construct 2 Release 152 (trying free edition for now)
Firefox 26.0 (to run the Layouts)
Results
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* Upon install, Construct 2 suggests getting latest video drivers which of course won't work, so didn't change them. However, I did up the resolution in the control panel.
* Loaded and ran both included demos successfully in C2 running through Firefox. However the frame rate and sound may be been a bit laggy. And, one of the demos gave a message about OpenGL not working but that was to be expected. Demo still played ok.
* Tested the problem experienced by the other person who tried VirtualBox
and it worked for my setup. Namely, I started a new project, dragged a PNG into it and ran layout -- displayed the image as expected (no gray box problems)
I am new to C2 so I have not put it through its paces, but there is no weirdness yet at this point.
Because of the impact of memory on speed in both my operating systems, I just ordered 8gb (2x4gb) RAM for about $60 to replace my 4gb. Because I think my OS X 10.9 especially is cramped running with only 2gb available to it. (But it does still seem usable with only 4gb total.)
I will update if I find any problems. Or let me know if there is anything specific I should test.
I also own VMWARE Fusion but its version is outdated and I can't run fusion under 10.9 without updating to version 6 and paying for a new license. So I am happy that VirtualBox seems to be a good free alternative. Just have to supply your own Windows OS license.