I noticed that the pstoimg script contains lines with $PNMCROP -bot ... This didn't work for me, I always got a black border on the left and at the bottom of math expressions. When I changed this to $PNMCROP -black ... (or $PNMCROP -b) it works ok. That's no wonder, since if I look at the dvi file created from images.tex, it contains a grey page, with the math formula in it in black, and two black rules at the left and at the bottom of the formula. Somewhere there must be a bug latex2html. (BTW: I am using the pnmcrop from netpbm 9.6)