Just in case ...
We recently had this error, turned XTrace logs for lddwnld and got the following log entries...
10/20/2014 12:51:41.014 4936 1264 lddwnld.cpp 3750 Calculating new hash for software_Packages\Microsoft_Office\2007\Source_Files\Project_2007_Over_Network_v4.exe since file time changed
10/20/2014 12:51:41.124 4936 1264 cache.cpp 454 GetFilePrevCountExWork: hash passed in bQyWBDYUdIFs/zRNC9DCZg== and current hash UdICsJTbDmKCV8u5rbYAiA== did not match
10/20/2014 12:51:41.124 4936 1264 lddownload.cpp 2167 GetFilePrevCount just returned no file and wrongVersion, so about to delete file
A simple reset of the package hash resolved this issue.