Hi
The best way to troubleshoot is to try it on a blank HTML page. Copy the code provided from the integraton page in your HTML page. Replace the value in all the [brackets]. For example, replace [url] with the URL address of the thumbshot you want to display (eg. try http://www.yahoo.com). Remember to remove the brackets "[]" too. Make sure there is no typo mistakes. Most errors occur because of a mistake on a single character. You should be able to see an image of thumbshot.
If that doesn't work, make sure you turn off any program that could inadvertently block images such as Norton Internet Security.
[++PAID++] If that doesn't work, make sure your ValidURL settings under Thumbshots.com > Manage > Options are correct. The ValidURL value should contain at least your domain name where you're hosting the page (eg. "mydomain.com" without the quotes).
Once good, you can replicate the code on the actual site. Find more support answers on our FAQ and Forum at www.thumbshots.org. Thanks for your interest :)
Sharmistha