suzi,
Tacoma Violets and Black Madeira both rooted without any issue for me. i have heard that some members do have an issue with Black Madeira and some others. i wonder if they are getting cuttings that are less then ideal for rooting. i notice that fresh cut cuttings rarely have an issue.
most cuttings i have received and very fresh and have no problem rooting. ones that are having problems are ones that i forgot to root quickly and end up rotting away. all my fault and not that of person who sent me the cuttings or the cutting themselves.