FTP 550 Error Access Denied Server 2008 IIS7

[ahoodin7]

I am working on a New version of a Winodws Server based product. It acts as a FTP Server for the most part, using IIS.

I have an embedded system that connects to it an successfully gets files off of it, however when it goes to write to it,
there is an error.

At first it gives Win32 Error 64 or ERROR_NETNAME_DELETED :

#Software: Microsoft Internet Information Services 7.0
#Version: 1.0
#Date: 2013-08-30 14:01:20
#Fields: date time c-ip cs-username s-ip s-port cs-method cs-uri-stem sc-status sc-win32-status sc-substatus x-session x-fullpath
2013-08-30 14:01:20 192.168.167.80 - 192.168.167.24 21 ControlChannelOpened - - 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:20 192.168.167.80 - 192.168.167.24 21 USER uCosUser 331 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:21 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 PASS *** 230 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 /
2013-08-30 14:01:21 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 TYPE I 200 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:22 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 PASV - 227 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:22 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 51928 DataChannelOpened - - 0 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:34 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 51928 DataChannelClosed - - 64 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 -
2013-08-30 14:01:34 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 STOR JOB.DAT 550 64 0 2b4bd559-f764-477b-98b4-3e0f6a3c9250 /JOB.DAT

After a server reboot it starts giving Win32 error 2 or Access Denied:

2013-08-30 15:07:33 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 PASS *** 230 0 0 adf3063a-c853-4abb-96f9-7766edec008f /
2013-08-30 15:07:34 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 TYPE I 200 0 0 adf3063a-c853-4abb-96f9-7766edec008f -
2013-08-30 15:07:34 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 PASV - 227 0 0 adf3063a-c853-4abb-96f9-7766edec008f -
2013-08-30 15:07:34 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 49223 DataChannelOpened - - 0 0 adf3063a-c853-4abb-96f9-7766edec008f -
2013-08-30 15:07:35 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 49223 DataChannelClosed - - 2 3 adf3063a-c853-4abb-96f9-7766edec008f -
2013-08-30 15:07:35 192.168.167.80 SVR2K8\uCosUser 192.168.167.24 21 RETR JOB.DAT 550 2 3 adf3063a-c853-4abb-96f9-7766edec008f /JOB.DAT

I looked into these things a bit, and tried switching in code from passive FTP to active, and the same thing is still happening. When I called IT about it,
the system admin seemed adamant that it was GROUP policy. The funny thing about this is that the FTP server isn't on the public network, it is on a private
network for devices only. Also we have Windows Server 2003 based products that do the same thing without a problem.

What could it be?