Those trying to submit their product feeds to Google Base or Merchant Center may be running into errors. Ronald from the Google Merchant Center team has confirmed a bug that Google's engineers are working on fixing.
A thread at Google Merchant Help has confirmation, where a Googler said:
We're currently experiencing an issue with data feed processing. If the data feed status shows as "Internal error, feed not fully processed" without any error message, please resubmit your data feed. Our engineers are working to resolve this issue.
We appreciate your patience!
There is currently not estimated time of a fix but it is good to know that Google is aware of the issue.
Forum discussion at Google Merchant Help.