I do not have a clue as to what is going on here, nor do I know how "important" it is given that I know that it exists and how to easily circumvent it, but the following is complete, precise, documentation of the situation at hand:
At this point, I have done this literally dozens of times, with similar results (the reason I use the word "similar" is because the exact byte offsets and differences vary from test to test, although the byte offsets are always approximately (within one or two bytes) the same).
I don't want to "distribute" the file in question because I suppose it might be proprietary, but it is freely and readily available from http://memory.dataram.com/products-and-services/software/ramdisk, just click on the button on the far right at about the middle of the page "Download It Dataram RAMDisk (3.0MB)". And just to be "complete" about it, I ran "just-updated" copies of both "Malwarebytes Anti-Malware" (http://www.malwarebytes.org) and SpyBot Search & Destroy (http://www.safer-networking.org/en/index.html) before I made this posting, and no "malware" nor "spyware" were found; and "AVG Anti-Virus" is always present and running. And finally, drive "D" is a completely "ordinary" partition on the physical hard disk of my laptop (not RAMDisk).
TCC 12.11.74 Windows 7 [Version 6.1.7601]
HTML:
[D:\JP Soft Demo Directory]dir
Volume in drive D is Data Serial number is e4fa:ef04
Directory of D:\JP Soft Demo Directory\*
9/18/2011 13:45 .
9/18/2011 13:45 ..
9/17/2011 23:53 3,141,120 Dataram_RAMDisk_V3.5.130R19.msi
3,141,120 bytes in 1 file and 2 dirs 3,141,632 bytes allocated
6,650,011,648 bytes free
[D:\JP Soft Demo Directory]md Test /D
[D:\JP Soft Demo Directory\Test]copy ..\Dataram_RAMDisk_V3.5.130R19.msi . /O
D:\JP Soft Demo Directory\Dataram_RAMDisk_V3.5.130R19.msi => D:\JP Soft Demo Directory\Test\Dat
aram_RAMDisk_V3.5.130R19.msi
1 file copied
[D:\JP Soft Demo Directory\Test]fc /b ..\Dataram_RAMDisk_V3.5.130R19.msi Dataram_RAMDisk_V3.5.1
30R19.msi
Comparing files ..\Dataram_RAMDisk_V3.5.130R19.msi and DATARAM_RAMDISK_V3.5.130R19.MSI
0000046C: B0 E0
0000046D: 09 8E
0000046E: 15 33
0000046F: C4 36
00000470: 5F 33
00000471: 62 76
[D:\JP Soft Demo Directory\Test]del Dataram_RAMDisk_V3.5.130R19.msi
Deleting D:\JP Soft Demo Directory\Test\Dataram_RAMDisk_V3.5.130R19.msi
1 file deleted 3,141,632 bytes freed
[D:\JP Soft Demo Directory\Test]cmd
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
D:\JP Soft Demo Directory\Test>copy ..\Dataram_RAMDisk_V3.5.130R19.msi .
1 file(s) copied.
D:\JP Soft Demo Directory\Test>fc /b Dataram_RAMDisk_V3.5.130R19.msi ..\Dataram_RAMDisk_V3.5.13
0R19.msi
Comparing files Dataram_RAMDisk_V3.5.130R19.msi and ..\DATARAM_RAMDISK_V3.5.130R19.MSI
FC: no differences encountered
D:\JP Soft Demo Directory\Test>
I don't want to "distribute" the file in question because I suppose it might be proprietary, but it is freely and readily available from http://memory.dataram.com/products-and-services/software/ramdisk, just click on the button on the far right at about the middle of the page "Download It Dataram RAMDisk (3.0MB)". And just to be "complete" about it, I ran "just-updated" copies of both "Malwarebytes Anti-Malware" (http://www.malwarebytes.org) and SpyBot Search & Destroy (http://www.safer-networking.org/en/index.html) before I made this posting, and no "malware" nor "spyware" were found; and "AVG Anti-Virus" is always present and running. And finally, drive "D" is a completely "ordinary" partition on the physical hard disk of my laptop (not RAMDisk).
TCC 12.11.74 Windows 7 [Version 6.1.7601]