I've installed strace to investigate further:
hoefnix2:~# strace vzctl enter 60
...
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x2b65860859d0) = 29577
close(3) = 0
close(7) = 0
close(9) = 0
close(10) = 0
read(8,
With bash 4.1 patchlevel 009 I get:
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x2af2938ab9d0) = 2972
close(3) = 0
close(7) = 0
close(9) = 0
close(10) = 0
read(8, "", 4) = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 1), ...}) = 0
...
Hope that someone sees the problem and may be even a soultion .