Cookie created but lead not found

[Anonymous]

We are appending source tracking values to anonymous values using the SOAP API. About every 75 records or so we are getting a cookie value that isn't found when we try to load it from Marketo.

We have verified that the format looks correct and that the cookie value starts with the Munchkin ID that is on the site.

Does anyone know of a process or case that could cause the cookie to be created an populated with a value but have it not be created in Marketo itself?

Thanks

L

[Anonymous]

The Munchkin JS creates the cookie then fires a tracking http call via the browser

if that http call failed, then Marketo wouldn't know about that cookie created by the JS