Vanilla Forums COO [GitHub, Twitter, About.me]
Re-installing isn't working. Somehow, the Theme Options is remembering that I (mistakenly) typed something in the text box. Even though I replaced the default.master.tpl with the old file, it's just not showing an image again.
This is weird.
AND I reinstalled the theme. 2.0.18 seems to be remembering my mistake.
And by "external" image, do you mean it can't be put in the root directory of the forum?
Delete .ini files in cache folder.
Deleting the .ini files didn't work