source plugin won't load

[tschumann]

I'm trying to make Half-Life 2 Deathmatch plugin, but I can't get it to load.
I've set -insecure and -allowdebug on the command-line but it just keeps printing:
Loading unsigned module addons\serverplugin_empty.dll
Access to secure servers is disabled.
Unable to load plugin "addons\serverplugin_empty.dll"

I've tried to make the Load function return true all the time as well, but it still says the same thing.