The portal template try to set the width of which is rigidly in place:
<td valign="top">
{$announcements}
</td>
give:
<td valign="top" width="500px">
{$announcements}
</td>
Instead, '500px ', you can enter any other value.
Ok i did that but for a second its the right size and then switches back to the old one, the big one.