I have exactly the same problem, I have W995_R1EA028_MAIN_GENERIC_HI_RED53, W995_R1EA028_FS_WESTERN-EUROPE_RED53 with C905_1209-4774_R6A_GENERIC_WESTERN-EUROPE custpack. I have tried a few custom_upgrade.xml from various countries but cannot get SEUS to upgrade to R1HA036. It sais I am using the latest version available. There is no "upgrade anyway" option. I have done all the switch on and off, remove and replace battery. Any ideas much appreciated.