Cannot updoad Firmware.hex over web because file too big (6 MB)

I am using version 4.3 r4 with a G400 raptor board. I have used InFieldUpdate to update both firmware and application successfully using an SD card. Now I need to upload the 3 hex files (config.hex, firmware.hex and myApp.hex) from the web so that I can write them to the SD card. I can upload and receive config.hex file because it is only 6 KB. But when I tried to upload firmware.hex, I don’t receive anything at all over the web. Can you tell me how I can accomplish this? Thanks.

@ nsmith - Can you post a minimal but complete example that shows the issue?