rationalskepticism.org

Spearthrower wrote:

Thomas Eshuis wrote:Can a native speaker riddle me this; why is dynasty, pronounced as di-nah-stee while dynastic
is pronounced as die-nah-stic?

Both can be pronounced either way. I'd pronounce them both as in your former example.

Strangely, the OED claims that in British English, the 'proper' pronunciation is I described in my original post.
I would've thought that changing a noun into a adverb wouldn't unnecessarily change the pronunciation.