Your problem is not with the PayPal item button code but, more with your web site and/or site HTML Editor. The PayPal item button code is a basic HTML Form. What you need to do is find out how your web site and/or site HTML Editor handles HTML Forms.
Check with your web site Host's Tech Support or if they have a Forum, search or ask. Note, some web sites do not allow the use of HTML Forms while other sites do however, the site HTML Editor must be in a specific mode or view before you can insert the item button code.
Should you find out that your site does not allow HTML Forms, most likely you can use text or hyperlinks. The PayPal online button creator can generate what we call an email link version of the item button code. You can then take this code and insert it into your web page as a text or hyperlink.
Tip:
You can build your own Button Text Links from scratch or take advantage of the Online Button Creator within your PayPal Account. After generating the button code online, select the "Email" tab to view the Text Link Code. Note, the "Email" tab will not be available if have included dropdown selections or text boxes in your item button code. This is because you cannot include dropdown selections or text boxes in a Text or Hyperlink.
To see some Tips and Examples, check out this page.
Regards,
skier
