How do you drag a photo there if it is in iPhoto? Where does iPhoto store it's photos? Is it even legal to just copy fotos out of the iPhoto folder?
I also tend to have problems on OS X because the finder sucks and dragging files to the task bar -> window opens -> drop on window often does not work for me (I suppose it should work?). If you open the finder, it hides the email window...
Just drag the photo from iPhoto to your new mail. Be strong, there's a lot of good magic involved(;
Also, iPhoto stores the pictures pretty conveniently as you might expect: ~/Pictures/iPhoto Library. And of course you can copy the files out of there.
And finally, you might want to get a screen that can fit a new mail and a finder window next to each other. A 13" monitor should do that just fine, btw(;
I also tend to have problems on OS X because the finder sucks and dragging files to the task bar -> window opens -> drop on window often does not work for me (I suppose it should work?). If you open the finder, it hides the email window...