What is CodeIgniter doing to my POST data!?

[eluser]Emkay[/eluser]
I am trying to use the tinymce editor http://tinymce.moxiecode.com/ with my private messaging system. The problem is that when formatting is applied, the message is not saved properly into the database.

For example <span color=""></span> tags are distorted and the color attribute is entirely omitted. It is similar with lots of other tags. Why is it going this? Does it have have something to do with automatic filtering when I use $this->input->post?

I tested the same form outside of the codeigniter enviroment and it doesn't have this problem. All tags are intact and the wysiwyg form works flawlessly.

As you can see I'm a but of a noob with input security, can anyone advise me on how to fix this problem and also make the form still as secure as possible?