softraid0 is part of every 4.3 dmesg, it's simply a stating support is enabled in-kernel.
As for your CF problem, not a clue, a change 4.3 enabled DMA on 1-sector devices, but it shouldn't be enabled if you device doesn't support it.
In the boot UKC, change the flags for wd* devices to 0xcff, this will force a PIO 4 mode and leave DMA/UDMA disabled.
If that doesn't help, the problem lies elsewhere.. hope it helps.