Do you have the photo you wish to save on your computer?
If so, go to your Photobucket.com , upload it and where it says Reduce click on the little arrow there and select 160 X 120 (small), that is your signature size.
Choose the photo you wish... copy the img address, which is the one on the bottom of the four.
Go to Preferences to Signature Box.. Paste the img address into the box.
At the bottom, click update my information.
Back to letter you are writing..
Finish your letter and be sure and click on Show Signature...
Click on Preview to see if it "took"...
Close Preview Window and click on Reply to Topic..
Hope this helped...Good luck!