Did you make sure that you placed the recovery image in the same directory as fastboot? I didn't see any mention of this, having an unlocked bootloader, you should be able to flash recoveries just fine.
Main version should also NOT affect weather or not you can flash a recovery, the version relates to what RUU/Kernel/ROM you can flash.
Man, I completely gapped the fact that he's trying to load Amon-Ra. I saw Mainver and started down my "flashing a kernel" thought path. Listen to MacPro...Not me...he clearly pays attention. lol
Ok, so the quick and dirty checklist
1) HTCDev Unlock
2) Amon-Ra(try grabbing 3.10)
3) HTC drivers installed(http://mypcdominion.com/Files/android/ROM_Tools/HTCDriver3.0.0.007.exe)
4) Fastboot, ADB + Dll's(http://mypcdominion.com/Files/android/ROM_Tools/CarePackage.zip)
5) Reboot into HBOOT(should say fastboot USB)
6) "fastboot flash recovery amon-ra.x.x.x.x.img"
7) ????
8) Profit
Im kinda perplexed as to how your main version changed? and why that would have effected you installing recovery, what what your main version by the way?
It also sounds like you have a PH zip on your sdcard that HBOOT is trying to load, take that off so there is nothing interfering with what you are trying to do.
Take all PH zips off your SD card, I think that may be your problem, HBOOT Bootloader will ALWAYS try to load these even if already loaded, so once you have loaded a PH zip you need to take it OFF asap to prevent problems.
Once you have taken them off, I want you try fastboot again. Boot into HBOOT and tell me what your main version is, you should see in green text: "HBOOT-X.XX.XXXX" that first number indicates what your main version is, right now, from the OTA it should be a "2."
Below, you should see "FASTBOOT USB." If you DO NOT see the USB part than the drivers are not installed, if USB is shown after fastboot, than you are good to go.
Now, with the recovery of your choice, place the .img (image) file in the SAME DIRECTORY as the fasboot program file (so if fast boot is in C:\android\platform\ than place the image file in that same folder). Make sure you are not placing the .zip file in there but the actual .img image file.
Then you can run, type this word for word: "fasboot flash recovery [name of the file].img" and make sure you included the file extension, .img, and also the partition to which you are flashing "recovery."
if anything even a little bit is off it won't work. "fastboot" is the program, "flash" is the command, "recovery" is the partition, then give the name of the file you want to flash along with the file's extension.
Hopefully this clears things up a bit...
try renaming the .img file as something shorter, like "amonra.img" or something, and you are sure that the .img file itself is the fastboot directory and not .zip file or anything else right?
And as I stated as well, you can always, RUU back to stock and start over, this will at least give you a botable OS for the time being.
I renamed it as well so it was shorter, same issue. I actually downloaded the RUU already, and it goes through the process and says it failed. Do I need to re-lock the bootloader to run the RUU? I used the 2.1 RUU since I have Hboot 2.1 and it doesn't like that one bit.
Guess I can try and download a stable rom from Scottsroms and dump it on the SD wipe and factory reset the phone and try and install that zip. Maybe it will work... I dunno I never had this many issues modding my moto phones before this guess HTC is too smart for me lol!