[Zope] reading of binary files

Hi, I encountered this problem when my product tries to load image files from the local drive. The code is below: file="blah" ob._setObject(file,OFS.Image.Image(file,file,"","image/gif")) data = f.read() ob._getOb(file).manage_upload(data) This works fine in zope under linux, but in zope under windows, the data is trucated. This is a python problem in windows. f.read() returns a string that is only a fraction of the length of the image file. Is there a way around this problem? Has anybody else encountered this problem? terry