Can't RedirectPermanent with spaces (%20) on URL

is it me or it can't be done?

[walkman]

Hi,
I'm trying to redirect an old format URL to the new one. /blah/some%20thing-blah to /blah/some%20thing.
I tried this:
RedirectPermanent /folder/some%20thing-blah [jfhuehgfegfyu.com...]
and I get a 404 instead of a 301 redirect when I type the old URL. What am I missing? Other redirects work perfectly and I tested some new ones too just in case. Unfortunately I'm stuck with the %20, it's not feasible to change it.

can this be done or I'm missing something?
any help would be greatly appreciated

[jdMorgan]

You can do this in mod_rewrite using the [NE] (noescape) flag on RewriteRule. I don't think you can do it with the Redirect directives.

Jim