Sometimes transformers seem to fail to connect and need a redstone state change before they start working(i.e. downwards transformers need to state changes)
Drop a transformer into prelaid wiring, and if it's placed in certain directions, it won't function till you apply and remove a redstone signal.
In the blockElectric source file, you are calling the setFacing function from the onBlockPlacedBy function. Change all these setFacing functions to alterFacing functions, as setFacing doesn't update the EnergyNet.(it's lines 171-191 in my decompiled version code)
Had same issue with my Power Regulator addon, applied this fix to it, it now functions correctly.
(not many bug reports come with detailed code fixing instructions and all, huh?)