dialer will not install

I am using Office 2007 on a Windows 7, 64-bit machine.When I try to install the dialer, I get an error message that reads "customize functionality in this application will not work because the certificate used to sign the deployment manifest for Ceptara SkypeDialer or its location is not trusted. Contact your administrator for further assistance. under the "details" section, it says the following:   Name: Ceptara SkypeDialerFrom: http://www.ceptara.com/iisdeploy/skypedialer/Ceptara SkypeDialer.vsto ************** Exception Text **************System.Security.SecurityException: Customized functionality in this application will not work because the certificate used to sign the deployment manifest for Ceptara SkypeDialer or its location is not trusted. Contact your administrator for further assistance.   at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInTrustEvaluator.VerifyTrustPromptKeyInternal(ClickOnceTrustPromptKeyValue promptKeyValue, DeploymentSignatureInformation signatureInformation, String productName)   at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInTrustEvaluator.VerifyTrustUsingPromptKey(Uri manifest, DeploymentSignatureInformation signatureInformation, String productName)   at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.VerifySecurity(ActivationContext context, Uri manifest, AddInInstallationStatus installState)   at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.InstallAddIn()The Zone of the assembly that failed was:MyComputer  Can anything be done about this? thanks