If you're using the link checker tool on amazon then a lot of times it won't work because the amazon capsule on hubpages is different to normal links on a website or blog.
One way to check that your amazon capsules are working is to click through on the links (you can do this with amazon links but not adsense). Then the next day log into your amazon associates account and see if the links have registered (remember though that Hubpages ID is shown 40% of the time).
Another way to check is to right click the hub and select view source. Check through to find your amazon ID. You might need to refresh a few times as it might be Hubpages ID showing or even the ID of someone who has referred you to the site.