In the Vista SP1, only the files smaller than 20 MB can be uploaded to the CIFS shared directory. The shared space is insufficient for uploading a file larger than 20 MB. By contrast, in the Windows XP, the file can be successfully uploaded because 20 GB shared space is allocated.
The problem is caused by inherent defects of the Vista SP1. It can be resolved if you map network drives in the Vista SP1 operating system.
To resolve this problem, you can map network drives to file systems according to the previous procedure.