Image and Text Align Doesn't Work

Guys please help me with this. I'm been trying to figure this one out for 5 days now to no avail.

All the align (Left, Right, Center, and justify for text) attributes I'm setting for my text and images does not seem to work at all when its saved and viewed already. This just seems to be fine though during editing.

I have read couple of post here regarding this and I have tried the solutions therein but none does work. I tried setting the 'Editor CSS' to 'TinyMCE default' -- not working. I have tried messing around my theme CSS and change the alignment of the 'body' -- still not working. I tried the older stable version of TinyMCE -- got worst, does not seem to work with D6.2. I tried adding this into my stylesheet

img.centered {
	display: block;
	margin-left: auto;
	margin-right: auto;
	}

img.alignright {
	padding: 4px;
	margin: 0 0 2px 7px;
	display: inline;
	}

img.alignleft {
	padding: 4px;
	margin: 0 7px 2px 0;
	display: inline;
	}

.alignright {
	float: right;
	}

.alignleft {
	float: left;
	}

-- still, nothing. And some other stuff I found from the other forums but none are working.

Please guys what am I missing here?

While we're at this I have another problem regarding ImageAssist/DrupalImage not appearing into my TinyMCE editor. (they say the solution here is to change TinyMCE 2.1.3 stable but it does not work with D6.2.

Info:
TinyMCE 3.1.0.1
TinyMCE-6.x-1.1-dev
Image assist 6.x-1.0-beta1

Help!