Does anybody know why the embeeded link of youtube videos aren't displayed in XOOPS forum?

my version is 2.0.15

it looks like as I copied in:
<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/GkJLGG_rfdk"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/GkJLGG_rfdk" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>

You need to enable html to see the video's in the forum

thx :P
somehow two of the forums have HTML disabled :)