That's pretty weird.

The buttons, like the lime, are .gif images. They should be inside limewire.jar (a jar is a zip file with another extension. You can open it in winzip or winRAR or whatever)

Check that within the jar, the folder com\limegroup\gnutella\gui\images is there, and that it has the images in it. notsearching.gif, searching.gif, button1.gif etc.

No idea why they wouldn't be, but that's all I can think of at the moment.

And BTW: interesting screen shot. That's the first time I've ever seen the ads in LimeWire (I always compile it without, and the screenshots on limewire.com are of the pro version which is ad free)