URI changes . to _ (best practice?)

[eluser]WanWizard[/eluser]
I'm very intrested in the bit of code that would actually perform such a change.
So far, I haven't been able to find it, and I can't find a server to recreate this problem on as well.

I think it is very unlikely that CI would suddenly (sometimes it does, sometimes it doesn't?) decide to modify the URI, and then redirect to it?

I have a feeling there is an external force at work here... Try to find the cause of the problem, instead of nasty kludges to work around it...