I deleted my old question as I found the solution, but came up with a new one.
Colour management - what the hell is going on here? In photoshop, my sRGB files look more saturated than they do in firefox or safari. If I choose "Monitor RGB" and proof colours the look in photoshop exactly matches firefox, but if I turn off proof-colours everything looks much more saturated.
I would have though photoshop would be working in the same space as firefox/safari by default; sRGB, using my LCD monitor. Anybody have any tips? Should I just edit with "proof colours" for "Monitor RGB" turned on? Will this throw me way off for any future printing? I've not got profiles for any particular printer (I haven't been printing much colour lately, mostly traditional darkroom B&W).