is the mozilla bug. Seems we have the same bug.
Is a test case. Uploading said test-case to bugzilla seems to cause a 500 error. Not sure why.
The right fix seems to be to hack dftables.
We have a (failing) test for this in ecma_3/Unicode/uc-002.js. Note that uc-001.js also fails, and that is tricky, see bug 4931 and bug 10183.
The regular expression issue is bug 20966, and was fixed by the introduction of WREC on 32-bit x86 (or at least Mac and Windows), and by r36612 on other platforms. Is there any other case where we treat a non-breaking space differently, or can this bug be closed?
nbsp works in regular expressions, source text, the bugs Alexey linked to are marked fixed, and ecma_3/Unicode/uc-002.js passes. Works for me.