Questions
Why the posts are not saved by Guestbook system?
Why the captcha image is not showed in the insertion form?
Why the error message "The security code is not valid." is showed if the captcha text is correct?
Can be used the Reviews Bubble in combination with any reviews manager?
Answers
Why the posts are not saved by Guestbook system?
The posts are saved in a XML file inside the "db" folder. You must be sure that the "db" folder have permissions for writing.
To set the permissions for writing you need:
FTP programs ("clients") allow you to set permissions for files and directories on your remote host. This function is often called chmod or set permissions in the program menu.
In the first image, look at the last column - that shows the permissions. It looks a bit confusing, but for now just note the sequence of letters:
Why the captcha image is not showed in the insertion form?
Why the error message "The security code is not valid." is showed if the captcha text is correct?
Can be used the Reviews Bubble in combination with any reviews manager?
No, the Reviews Bubble can be used only in combination with the Comment System and the Guestbook extension.