Mark,

One more thing to check which may be the cause of why the 4MB SIMMs
aren't recognized as more than 1MB: the IIcx may require that you use
8 chip (or 9 chip, the extra parity chip will be ignored) SIMMs,
rather than 2 chip (or 3 chip) SIMMs.  I don't know if this is true or
not; all I know is that some older computers (not just Macs) which
used 8/9 chip SIMMs don't work with 2/3 chip SIMMs.

John