Blog pages are displayed differently in Firefox 3.5.x and IE 6.0.
This is how it is displayed in Firefox 3.5.x (no issues):
This is how it is displayed in IE6.0 (issues are marked red):
Issue 1 - no round in tabs.
Issue 2 - no transparent background in the search icon
Issue 3 - Date and post title problem (new line)
Issue 1 and 2 present in both 3.1.0 and 3.1.5
Issue 3 is new for 3.1.5.
