I discovered this problem when viewing the dedicated (cmd) and had the following text:
Sending 'gfx/classic_superhero/sh_oval_1.png' to Player...
Sending 'gfx/classic_superhero/sh_oval_2.png' to Player...
Sending 'gfx/classic_superhero/sh_oval_3.png' to Player...
Sending 'gfx/classic_superhero/sh_oval_4.png' to Player...
Sending 'gfx/classic_superhero/sh_penguin.png' to Player...
Sending 'gfx/classic_superhero/sh_machete.png' to Player...
Sending 'sfx/starkkz/mod.wav' to Player...
Sending 'sfx/starkkz/admin.wav' to Player...
Sending 'sfx/starkkz/powered.wav' to Player...
Sending 'sfx/nuke.ogg' to Player...
Sending 'sfx/starkkz/welcome.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/doublekill.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/humiliation.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/monsterkill.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/multikill.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/ultrakill.wav' to Player...
Sending 'sfx/starkkz/glados_utsfx/unstoppable.wav' to Player...
Sending 'maps/sh_dust3' to Player...