.dat file truncated when downloaded from a web service IIS6.0 that has been published in a remote win 7 desktop successfully

Question

This question is related to my previous question.

I have published a web service application (C# built in VS2010) to a desktop with IIS 6.0 win7.

The web service has been hosted successfully.

Now I can install the application on my laptop by accessing the URL

http://myDesktopName.domain.com/MyApp/MyAppSetup.msi

pointing to a physical location in desktop

E:\myPath\myApp\myAppService.svc

Now, in my application, I need to download a .dat file from my desktop to my local laptop by visiting the URL.

"http://myDesktopName.domain.com/MyApp/download.ashx?cmd=download&type=db&name=myDatasbase.dat"

But, the downloaded file size is not correct. Sometimes, it is 0. Sometimes, it is 9KB or 64KB. But, the original size s 4,000 KB.

The file is binary and is not readable in any text editor.

If I download the file from IE by typing the URL

http://myDesktopName.domain.com/MyApp/download.ashx?cmd=download&type=db&name=myDatasbase.dat

in address bar, the file can be downloaded correctly.

Why the file cannot be downloaded correctly from my application ?

thanks