I seems that a majority of the question was cut off. It will not show the rest of the octet-stream in the MIME data, and it did not show the log from the device. Here is the log since I think that will be relevant.
1/httpupload: LogFileUpload: Begin processing file "/var/log/modbus/mb-001.50CDBE8F_1.log.gz" ----------------
1/httpupload: TCPConnect: Connecting to server 192.168.1.163:80 (via 192.168.1.163:80).
1/httpupload: TCPConnect: Established connection to server 192.168.1.163:80 (via 192.168.1.163:80).
1/httpupload: SendDataFile: Start file: "/var/log/modbus/mb-001.50CDBE8F_1.log.gz" as "/var/log/modbus/mb-001.50CDBE8F_1.log.gz" (size 11240).
1/httpupload: SendDataFile: Original log filesize = 11240, total bodysize = 13116.
1/httpupload: SEND: POST HTTP/1.0
Host: 192.168.1.163:80
1/httpupload: SEND: Connection: close
1/httpupload: SEND: Content-Length: 13116
1/httpupload: SEND: Content-Type: multipart/form-data; boundary=MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
1/httpupload: SEND: Pragma: no-cache
1/httpupload: SEND: Authorization: Basic MDAxRUM2MDUxMjIxOnBhc3N3b3Jk
1/httpupload: SEND: User-Agent: Mozilla/4.0 (compatible; httpupload.c 1.41; Linux; serial 001EC6051221)
1/httpupload: SEND: --MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="SENDDATATRACE"
YES
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODE"
LOGFILEUPLOAD
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="SERIALNUMBER"
001EC6051221
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="PASSWORD"
password
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="LOOPNAME"
001EC6051221
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSIP"
127.0.0.1
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSPORT"
-1
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSDEVICE"
1
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSDEVICENAME"
Power Meter Test 1
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSDEVICETYPE"
Obvius Power Meter Simulator
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSDEVICETYPENUMBER"
-1
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MODBUSDEVICECLASS"
74
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="MD5CHECKSUM"
edba30720900d5068bdd6a960d8a98c9
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="FILESIZE"
11240
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="FILETIME"
2012-12-16 12:29:02
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY
Content-Disposition: form-data; name="LOGFILE"; filename="/var/log/modbus/mb-001.50CDBE8F_1.log.gz"
Content-Type: application/octet-stream;
1/httpupload: SendDataFile: TCP connection MSS = 1448
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1448 bytes of data
1/httpupload: SendDataFile: Sent 1104 bytes of data
1/httpupload: SEND:
--MIME_BOUNDRY_MIME_BOUNDRY_MIME_BOUNDRY--
1/httpupload: SendDataFile: Finished sending file to remote server.