Hmm ... perhaps you're mixing-and-matching some options that don't work well together.
Try using the code below, and make sure the gplot comes out looking right - if it doesn't look right, maybe something in your autoexec.sas, etc, isn't "playing well" with these options. Once you get it looking right, then swap your graphics proc for this 'proc gplot'.
filename odsout '.';
goptions device=gif;
goptions xpixels=400 ypixels=400;
ODS LISTING CLOSE;
ODS HTML path=odsout body="foo.htm";
proc gplot data=sashelp.class;
plot height*weight / name="foo";
run;
quit;
ODS HTML CLOSE;
ODS LISTING;