I did a clean install of SimpleClans, and now it checks for MySQL even if the option is off.

2011-08-29 15:30:39 [INFO] [SimpleClans] version 1.3.3 loaded
2011-08-29 15:30:39 [INFO] [SimpleClans] Spout features enabled
2011-08-29 15:30:39 [INFO] [SimpleClans] MySQL Connection successful
2011-08-29 15:30:39 [WARNING] Error at SQL Query: No database selected
2011-08-29 15:30:39 [INFO] [SimpleClans] Creating table: sc_clans
2011-08-29 15:30:39 [SEVERE] No database selected
2011-08-29 15:30:39 [WARNING] Error at SQL Query: No database selected
2011-08-29 15:30:39 [INFO] [SimpleClans] Creating table: sc_players
2011-08-29 15:30:39 [SEVERE] No database selected
2011-08-29 15:30:39 [SEVERE] Error at SQL Query: No database selected
2011-08-29 15:30:39 [SEVERE] Error at SQL Query: No database selected
2011-08-29 15:30:39 [SEVERE] Error occurred while enabling SimpleClans v1.3.3 (Is it up to date?): null
java.lang.NullPointerException
at net.sacredlabyrinth.phaed.simpleclans.SimpleClans.registerCommands(SimpleClans.java:109)
at net.sacredlabyrinth.phaed.simpleclans.SimpleClans.onEnable(SimpleClans.java:90)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:126)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:885)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:278)
at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:178)
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:161)
at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:286)
at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:273)
at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:149)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:337)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)

Tested this but cannot replicate. Download 1.3.4, delete your current SimpleClans folder, and let me know if the problem persists for you.