OAI-PMH Provider skips documents in certain cases

Our project makes use of the OAI-PMH provider. In certain conditions documents will be skipped and are not included in the output. This happens when the following two conditions are met:

• two documents or more have the same publication time
• this batch of documents doesn't fit into one delivered page

If this happens all documents not fitting into the current page will be skipped. The reason for this is the resumption token, that only specifies the time without actually including a hint to the last document delivered. For that reason the follow up request using the given resumption token will only deliver all documents older than the given time, thus skipping all documents with the same time stamp as the last document of the current page.