The new launcher is giving links such as:
http://losangeles1.creeperrepo.net/FTB2/modpacks%5EUnleashed%5E1_1_4%5EUnleashed-server.zip
which should be:
http://losangeles1.creeperrepo.net/FTB2/modpacks/Unleashed/1_1_4/Unleashed-server.zip
Part of the address is URL encoded when it shouldn't...