Images not shown when using AdBlock

Current nightly builds do not show certain images when AdBlock is installed. An example is Slashdot, where the images at the top right (and others) are initially not shown. Instead, their ALT text is displayed. Hovering over such images makes them appear. All AdBlock versions (0.5.2.039, 0.5.9 and 0.5.9.2_enh) seem to be affected. The AdBlock Plus Forum has a thread about the problem, and there even is a mozilla.org bug report. MultiZilla has similar, though unrelated issues (see corresponding bug report).