block_leftbar_top.png not showing in IE when the block has no title

I think the title of the post says it all... in IE, when I have a block in the left sidebar that doesn't have a title, the block_leftbar_top.png image isn't be displayed. When I give the block a title, both the title and the .png image show up as expected. This problem doesn't exist in FF. (Section of a screenshot from IE showing a sidebar box with and without titles is attached)

Here is the css code responsible for displaying that image:

#sidebar-left .block h2.title {
font-size: 1.5em;
color: #666;
margin: 0;
background:url(images/block_leftbar_top.png) bottom no-repeat;
padding-bottom: 11px;
}

#sidebar-left .blockinner {
background:url(images/block_leftbar_top.png) 0 0 no-repeat;
}

It seems that if there is no title or the title value is null, IE is choosing not to show the image. Hopefully someone more experienced than me can see from that code why IE is having a problem.

Any ideas, including a suggested IE hack? I can stumble my way through the css and php files, but I'm no expert.

Thanks for any help, and thanks to the creators for a great theme!

By the way, I have checked both the 6.x-1.0 and 6.x-1.x-dev versions and they both appear to have this problem.