Flash .swf loses quality when played in HTML

(I use Flash CS4)

I’ve made a flash banner which I want on my website. The quality was a bit crap so I searched around and found hundreds of places giving advice on improving quality, and I’ve followed some of these.
The quality of the images in the banner is top notch - when viewed on my PC. As soon as I upload it to my website, it goes to hell. The images become grainy and pixelated (although not as bad they were before the changes).

The images I use are all .PNG, imported into flash and NOT resized. They are all placed at whole number coordinates (x = 1 y= 1).
None of them are rotated or edited in any way.

The steps I’ve taken to improve quality:

I’ve gone to each individual image and set it to ‘Lossless PNG’
I’ve unticked ‘allow smoothing’.
I’ve ticked ‘allow smoothing’. <-- This removes the pixelated edges but leaves the images slightly ‘fuzzy’ and soft looking.

Ive changed publish settings for;

Jpeg quality to 100.
Enable Jpeg unblocking.
Unticked ‘compress movie’.

This is the code I use to call the .swf file. It starts playing automatically, and in High quality.

<a href="{U_INDEX}" title="{L_INDEX}" id="logo"><object classid="clsid27CDB6E-AE6D-11CF-96B8-444553540000" codebase="http://active.macromedia.com/flash2/cabs/swflash.cab#version=5,0,0,0" width="880" height="302">
<param name="movie" value="{T_THEME_PATH}/asmo.swf" />
<param name="play" value="true" />
<param name="quality" value="high" />
<param name="allowScriptAccess" value="never" />
<embed src="{T_THEME_PATH}/asmo.swf" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash" width="880" height="302" play="true" loop="true" quality="high" allowscriptaccess="never"></embed>
<p style="display: none;"><a href="#start_here">{L_SKIP}</a></p>

I’m at a total loss as to why, when the .swf is perfect quality on my PC, it loses quality on a webpage…

Any help is much appreciated.