IE8 problem with lists

[vanto]

Steps to reproduce:

1. Copy rich text content from http://xing.github.io/wysihtml5/ and paste it into advanced example on IE8 (you probably need to apply IE8 Node.compareDocumentPosition fix #19 and IE8 issue when wysihtml5 tried to call getAttibute on a boolean #20 first).
2. Select the bullet list and click insertUnorderedList. The bullet points disappear and the list is now text, line by line.
3. Keep the selection or select the same lines, click insertUnorderedList again.

Expected result: The bullet list appears in the same fashion as it was after step 1.
Actual result: Only the first line appears as bullet list. The other lines remain selected. After a second click on insertUnorderedList, the other lines will correctly set as bullet list, however, they are now wrapped in a second <ul>.

[vanto]

@pulges Any ideas what could cause this phenomenon and where to start with debugging?