I've validated all my maps, yet i only find two when i try to upload them, and, i get the message "You must validate your track before uploading it", even though i've validated it several times.

Have you saved since you validated, and if so, are you trying to upload the file you validated?

Also, have you computed shadows before you saved the maps?

First time, I saved, validated, did the shadows (fast), saved.

You also can't modify the map after validating it (not at all, you cant even add scenery). Validation & re-computing shadows is the last thing you do. So if you made any small changes, you need to validate again.

MrA says:
You also can't modify the map after validating it (not at all, you cant even add scenery). Validation & re-computing shadows is the last thing you do. So if you made any small changes, you need to validate again.

Not ingame mediatracker either. That used to annoy me

but it's right, since you can do such things in ingame that map won't be finishable.