list element names in S4 class extending list

can list names attributes be preserved through S4
class containment?  seems to be so but only if the containment
relationship is direct ... see below.

setClass("c1", contains="list")

[1] "c1"

l1 = list(a=1, b=2)
o1 = new("c1", l1)
names(o1)     # pleasant surprise

[1] "a" "b"

setClass("c2", contains="c1")

[1] "c2"

o2 = new("c2", l1)
names(o2)     # sad

NULL

sessionInfo()

R version 2.6.0 Under development (unstable) (2007-05-11 r41535)
powerpc-apple-darwin8.9.0

locale:
C

attached base packages:
[1] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "methods"
[7] "base"