[Greasemonkey] Gm 0.5 and UTF-8(?) issues

[Matthias Bauer]

I'm trying to move my scripts over to the Gm 0.5.0 beta base, but keep
receiving this error in the JS Console:

Error: uncaught exception: [Exception... "Component returned failure
code: 0x80004005 (NS_ERROR_FAILURE)
[nsIScriptableUnicodeConverter.ConvertToUnicode]"  nsresult: "0x80004005
(NS_ERROR_FAILURE)"  location: "JS frame ::
chrome://greasemonkey/content/utils.js :: getContents :: line 160"
data: no]

I suppose this means some of my scripts are not in UTF-8 format, so I
opened them in SciTE, set Encoding to UTF-8, and re-saved. Now it sure
looks like they're all UTF-8 files, complete with BOM, but I still get
that error. Any ideas how to fix it or get better debugging output?

-Matt