You can avoid this hassle all together by becoming a preimum member and upload pics directly to the forum from your PC (plus other benefits).
Updating this for 2009
So you are computer and internet illiterate and can't post pics from your computer. Don't worry, if kindergartners can do it so can you.
First create an account at PhotoBucket.
Choose a user name and password.
Enter a bit of personal information. YOU DO NOT NEED TO SUBMIT YOUR CELL PHONE NUMBER.
Thats it! Now you can upload photos from your PC. Just go to photobucket.com and select "albums & upload" under "my albums".
Click "Choose Files" and browse to the picture file on your PC.
You will have the option to save the file with or without personal comments.
Now click the text next to "IMG Code" (the code will be automatically copied to your clipboard).
Now to post the image on the forum. You simply right click in the forum text box and select"Paste" from the menu.
And Viola! You've posted a pic!