as far as i know it is OK.
330.30 Securing and Supporting
(A) General. Type MC cable shall be supported and secured
by staples, cable ties, straps, hangers, or similar fittings
or other approved means designed and installed so as
not to damage the cable.
But i have had people say "approved means" is to be approved for that purpose but some say "approved means" basically means an approved strap or tie that has been approved for general strapping.
All though there are staples that are designed for romex and bx cable and romex cable only. I dont see any difference in them but they are listed for two separate cables.
Last edited by Niko; 10/19/11 12:35 PM. Reason: added