HttpModules - Why using HttpApplication is a bad idea

I was using Darksider's page optimisation module to clean up and optimise my sites HTML gamerlobby.net This was working like an absolute champ up until the night I decided to go live. Leaving ELMAH for the last minute as it was so darn easy to implement, I started to struggle to get it to start logging. It made no sense. Database created, Connection String present and correct, modules and handlers referenced. WHAT CAN IT BE.
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