Hi,
TWG uses the space you give it in the iframe.
You should be able to test this by simply using e.g.
www.spiegel.de as include.
Are you sure you have defined the iframe like before?
If you are using Firefox you can install the webdeveloper plugin.
This can show you the iframes and other interesting things.
With the screenshot I cannot help you very much because I cannot see any of the source code.
have you defined the iframe with a fixed height and width? or with % because this is handled differently in ie and FF. this is quite importent here! because if you have % like 90% you have to define the percentages in all tags before as well (like html, body ...)
1.4 does have an fix for iframe include - but only for ie
.
Michael