@skinnylatte I suspect that it "works", but either your monitor can't upscale the low resolution coming from the Mac or the Mac can't figure out what to do with the EDID data from the monitor.
As others have mentioned, DVI and HDMI are almost the same thing with a different connector, so it *should* work pretty much every time.
Do you have any other monitors or TVs kicking around that you could try?