Thanks to the help of many of you, I have been able to unpack (with FMK), modify some of the files in the rootFS, and repack it (also using FMK).  For a reason that I cannot figure out, I cannot upload the modified firmware to the device.Things I have tried:Uploading modified firmware  (Upload doesn't even start, the webapp tells me that the firmware update has failed)Uploading unpack/repacked firmware with ZERO changes (Upload doesn't even start, the webapp tells me that the firmware update has failed)Uploading firmware from manufacture (Uploads fine, and and update is applied to system, no problems)ObservationsWhen I take the original firmware and just unpack/repack, it is the same size as the original firmware file, but does not hash the same. I'm wondering if there is a checksum somewhere that the firmware update utility uses that fmk does to account for.I am lost on what to try next.  Any ideas or tutorials that you could point me to would really be appreciated.  UPDATEDoing some further investigation, i ran both firmwares (original and repacked original) through a hex diff. I noticed that in the original firmware, everwhere that 0x00 0x01 occurs, in the repacked version, it is replaced with a 0x80 0x00. I'm hoping that this means something to someone...Thanks
Update D-Link firmware with Modified firmware
firmware