I have been doing a project with dreamweaver and implemented CSS.
After completion i id a Dreamweaver Browser Test Check and got the following as a report:

File U:\pax\Projects\pax_html work\Contact\contact.htm (Back to Index)
Error Unsupported value for the frameborder attribute of the frame tag.
Microsoft Internet Explorer 4.0, Microsoft Internet Explorer 5.0
line 23 <frame name="contactLeft" scrolling="AUTO" noresize src="contactLeft.htm" frameborder="NO">
Error The FrameSpacing attribute of the FrameSet tag is not supported.
Netscape Navigator 3.0, Netscape Navigator 4.0
line 11 <frameset rows="138,*" frameborder="NO" border="0" framespacing="0" cols="*">
also lines 13, 21
File U:\pax\Projects\pax_html work\Contact\contact.html (Back to Index)
Error The Link tag is not supported.
Netscape Navigator 3.0
line 9 <link rel="stylesheet" href="../main.css" type="text/css">
Error The BorderColor attribute of the Table Data tag is not supported.
Netscape Navigator 3.0, Netscape Navigator 4.0
line 119 <td height="13" width="52%" bgcolor="#FF6600" bordercolor="#FF6600">
Error The Class attribute of the Table Data tag is not supported.
Netscape Navigator 3.0
line 21 <td class="function_label" height="11" width="4%">
also lines 23, 27
Error The BorderColor attribute of the Table Row tag is not supported.
Netscape Navigator 3.0, Netscape Navigator 4.0
line 19 <tr bordercolor="#000066">
File U:\pax\Projects\pax_html work\DevaConfig\deva_index.xml (Back to Index)
Error The deva tag is not supported.
Microsoft Internet Explorer 4.0, Microsoft Internet Explorer 5.0, Netscape Navigator 3.0, Netscape Navigator 4.0
line 1 <deva type="index" version="1.0">
Error The index tag is not supported.
Microsoft Internet Explorer 4.0, Microsoft Internet Explorer 5.0, Netscape Navigator 3.0, Netscape Navigator 4.0
line 03 <index name="8515 Overview" title="platform_8515" type="url">
also lines 09, 15, 21, 27, 33, 39, 45, 51, 57, 63, 69, 75

Kindly advice.
Thanks,