The orange warning banner with the padlock was added because there's a bogus LW update showing up in search results. It's a 75.7 KB .exe & shows up as "Urgent LimeWire update - download & install now". If people download that thing they could end up infected. To try to prevent people from downloading a dangerous file, the warning banner was added to LW's interface.

If you updated from the LimeWire site itself then you're fine. It's only when people download & install an 'update' file that they see in their LW search results (a file without the padlock icon) that they can have problems.

The padlock symbol doesn't apply to music, movies etc...just to LW updates