Quite simply, trying to use the "Search" function in the "Memory Viewer" section of WiiRd causes a (Dump From Current Address) to 81800000 search, which is fine until you try and search the 90000000 memory range, since it tries to dump from 90000000 to 81800000, which as most people know, doesn't quite work.
Just thought I'd point that out, though there is always the chance it could be just me, since otherwise you'd think it'd of been found/mentioned by now.
It's not just you, I've had that problem as well. I think there are also some issues with the pointer search panel's RAM dump feature after the memory range has been changed IIRC.