In LC 3.0.1 when trying to open a wiki attachment in IE9, the file type gets corrupted(" extra characters such as  gets added in the file type) the end" and user gets prompted "Windows can't open this file".
Steps to reproduce:
1. Navigate to Wikis in LC using Internet Explorer 9 2. Access an existing wiki or create a new one. 3. In the tab "Comments","Version","Attachments","About" click on attachments. 4. Add a new file and try opening it or try open an existing one. In this case the uploaded file was called "New Text Document.txt". 5. Note that when opening the file internet explorer 9 prompt at the bottom asks if you like to open or save the file "New Text Document(2).txt" in this case. Note the extra  on the file type added. 6. When you click open or save the file does not open as a .txt. it tries to open as .txt - unknown type. It will also save as .txt
This only happens in Internet Explorer 9. Firefox and previous versions of IE are all working.
UPDATE: Also happening opening/downloading files in Files application.