Do you have SSH access? If so, as the user srcds runs as, do the following commands:
Code:
cd <srcds>
export LD_LIBRARY_PATH=".:bin:$LD_LIBRARY_PATH"
ldd -d -r <game>/addons/sourcemod/extensions/dbi.mysql.ext.so
And show the output. <srcds> should be the path that contains srcds_run and <game> should be the game's folder.