I have had this as well and sorted it our by putting<center> before the code and </center> after the code. Centers them for me.
<center><object height="373" width="425">
<param name="movie" value="http://www.youtube.com/v/hVQXrKDt_Dk&rel=1&color1=0x234900&colo r2=0x4e9e00&border=1"></param>
<param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/hVQXrKDt_Dk&rel=1&color1=0x234900&colo r2=0x4e9e00&border=1" type="application/x-shockwave-flash" wmode="transparent" height="373" width="425"></embed></object>
</center>
Just anther tip for those having problems aligning images left or right I found it easier just to add align="left" into the image code to wrap the text.
eg: <img src="http://uploads.co.za/files/g1shis5gzkgm5k7bm3b9.jpg" alt="cummins power solutions"
align="left" />