Error when using HTML or AG code in a guestbook message

Forgive me if this has been answered already and I have missed it while searching the archives. I just installed the Advanced Guestbook on my site last night through my control panel's CGI area. Anyway, I managed to get everything looking as I wanted it to and working properly until I tried to post a test message with HTML and then another with the AG code. If I use the bold codes in AG code things work fine, but using the image tags will give this message when you submit: Your message contains some invalid words. Please correct it and re-submit. Any help would be greatly appreciated.

Thank you,
Dysis

I guess it would have helped if I had signed in first. Sorry about that.

Dysis

i dont know the answer, maybe you could look in the lang. file and see whats written in the instruction there might help