Currently, the Left Frame is not very usable when large font sizes are used or when it is resized.
This was mentioned in the Usability Report:
"Users may be confused by the appearance of the left hand frame if they try to adjust its width. R: Make sure that the legibility of the frame contents is maximised when the frame width is adjusted."
I'll try to look into it soon. I need to switch over to the SVN version first.
Update: Night draws near. I'll try to investigate further tomorrow. If I don't get to it tomorrow, it may not be until June 6th when I will get to it because I have a family reunion from June 1st to 4th and most people are not leaving until June 5th.
back to cms/css/cms_left.css fixes the problem of the other sections being broken. The only downside is that there is a different background color behind some of the links when the left frame's size is reduced. That's not a problem.
I'll plan on eventually creating a new patch that addresses the "Site Content", "Newsletters", and "Security" sections. However, if you want to fix the Site Content without breaking the other sections, just uncomment "height: 23px;"
Yeah, the background missing is caused by <li> elements having the float: left CSS attribute, and the container <ul> doesn't have this - so the background contents gets erased. If you add float: left to the <ul> it fixes that problem, but the other sections are still broken - this potentially could take a while to fix properly.