failure: bytes-read=-1 bytes-expected=-1 ???

System

we are intermittently getting this error on our production deployments on XML files - any ideas?

the xml files are valid and open fine in IE/firefox

LIB: 2009-06-17 11:22:26 Sending [.\assets\PR\FeatureStories\closetcleanout--200_Max_JPG_PR_News.jpg] [reason file_list]
LIB: 2009-06-17 11:22:26 Sending [.\assets\PR\FeatureStories\closetcleanout--JPG_tn.jpg] [reason file_list]
LIB: 2009-06-17 11:22:26 Sending [.\templatedata\PR\FeatureStories\data\CS_PR\AI_8961_Closet_clean_out__Get_your_clo.xml] [reason file_list]
LIB 00032: 2009-06-17 11:22:26 ERROR: File(Y:\default\main\common\WORKAREA\content\templatedata\PR\FeatureStories\data\CS_PR\AI_8961_Closet_clean_out__Get_your_clo.xml) failure: bytes-read=-1 bytes-expected=-1.
LIB: 2009-06-17 11:22:26 ERROR: deploy-failed.
LIB: 2009-06-17 11:22:26 Receiver-ERROR: ERROR: deploy-failed.
LIB: 2009-06-17 11:22:26 ERROR: Failed to deploy local_directory[.] of area[Y:\default\main\common\WORKAREA\content] for filelist[D:\Interwoven\Teamsite\tmp\Content_Publish_Workflow_1245251981605.log]
LIB: 2009-06-17 11:22:26 ERROR: Failed 1 of 1 filelists