I am also running an A3000 SCSI CF and SFS and can say that Mask issues were an issue for me and I couldn't get it right.
Until, I read the docs from the SFS website, since then it has been fine.
I think there is mass confusion about Mask and Max transfer settings and there are many variables that affect what your safe setting is.
Either way, I had issues initially and once reading the docs/faqs it has worked amazingly well.
