Digital Signature not showing on .pdf all the time

I have created a form with a digital signature field, which sporatically works. I am using a Topaz.gemsignplus (T-L-462-HSB model) to sign the form. Many times I have to sign the form multiple times to get the signature to appear on the .pdf. I will click the signature field, and sign the signature pad, choose "accept", but the signature field will not process the signature (the signature screen disappears, but the signature field remains blank, and can be signed again.) If I click the signature field again, go through the same signing process, the .pdf will accept the signature, and it will appear on the form. Many times the signature will be accepted the first time it's entered, other times it takes multiple signatures, if it accepts the signature at all. My digital signature preferences are set to: "Verify singatures when doc is opened"- checked. Under the Verification field: "Require certificate revocation checking to succeed whenever possible during signature verification" - checked.
Any ideas what I'm doing wrong?