Richard, Yoa are right about i/o based devices being active in whatever slot you place them. The slot select system only affects memory space, not I/O space. It is therefore easy to get a conflict with overlapping i/o addresses, especially since not all manufacturers did a good job in decoding the i/o address. Quite often the decoding is so limited that a whole block of i/o addresses is occupied.
It might be that a slight modification of the I/O addresses of one is required to have two Music modules working together with SMe. That mod was published with the SME editor. See my website for a pdf file. To disable a ROM to have just a SCC funtion, dont desolder the ROM but add a switch. Also documented. -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
