Ok, i don't have any clue about the IC² code
I just tested this on my server and after adding 140:1 to the config file, my miner found lots more of ruby, sapphire, tungsten, emerald (and nikolite) even on spots that were mined and finished before.
Maybe there is something wrong with my server that i had to add this to the config?
I tested it more further.
My server setup:
Redpower 2.0pr5b2 (Tin and Copper Ore disabled, because i also use Forestry)
Minecraft Forge 126.96.36.199
With the miners config @ default it will only mine the RedPower Ores when they are in it's way to his target. I.E. it's digging down and there is a ruby block directly below the miner, or when there is some Nikolite between the borehead and some iron ore the miner is going for.
But if there is some RP stuff around the borehead without any other "known" ore behind it, the miner won't touch it then.
When i add the RP id (140:1) to the config, the miner starts to search also for the RP Gems, Tungsten Ore and Nikolite.
You say it's in the code and forge got it's oredictionary, for some reason it is then not working on my server by default.