GD graphics extension question

BlankGD config problem, Windows problem, browser Options issue, or something else? I can't seem to figure this one out. (I'm still newbie to php, trying to learn on my Win98 pc at home. ) * * * * * * * GD is properly showing up on the phpinfo page as enabled. But when I click on several different test files (one from Weblogs, and one a test file for a particular class of graphs), the result is either: a) the Windows download dialog box launches for some reason (this happened for two different test graphic files, one being the Weblogs test file posted on their site) OR b) the following 2 errors occur (this happened for a particular graphics class test page): " Warning: Could not find/open font in classcoxcomb.php on line 462 " " Warning: Cannot add header information - headers already sent by (output started at classcoxcomb.php:462) in classcoxcomb.php on line 153 ‰PNG  IHDR
hðy}?PLTEÿ ÿÿ€€€€€€€€€€ÿÿÿÿÿÿÿÿÿðððîîîÝÝÝÌÌÌ333f ...etc.... " Most oddly, at one point after hitting the refresh button, the Weblogs test graphic all of a sudden DID appear. So I clicked refresh once again immediately (because I couldn't finally believe my eyes!) and, heck, once again the download dialog box launched, rather than the graphic appearing again. Now that was weird. Does anyone have a clue what I am doing wrong? [Three weeks now trying to figure this out on my own. I have (hopefully very carefully) checked all the windows archive mentions of "GD" and have perused same at other php forums. Nothing has yet hinted at my partcular GD goofup. By way of proof of newbieness, let me note for amusement sake that much of those 2 weeks was spent figuring out why php would hang every time I uncommented the php_gd.dll. Naturally....the cause was a bonehead typo done when typing my extensions directory path in php.ini--- i.e., I forgot to include the subdirectory name "/extensions" at the end of the extensions address on my pc--the extensions path in php.ini should have been c:/mystuff/php/extensions rather than c:/mystuff/php i hate that].