SetSelection adds a SPAN, but removes other HTML?

[AlanO]

Just wondering if I should log a bug... can someone else check my code
- I'm sure it's correct. There is a pretty big Regular Expression
inside and it doesn't strip other HTML out of the selected text... but
once SetSelection is called it seems to not insert the original HTML
tags.

http://kollektive.com/ubiquity/

synonyms: links, parse links, urls, url

"links Parses selected text and replaces any URLs found with HTML
links. Recognises most common protocols, even creates mailto: links
for email addresses. Now works with the new parser in 0.5"

I've just updated it for the new Parser in 0.5, so I thought I might
take a stab at working out why that never worked entirely anyway in
0.1