When using 0.6.8 on a xen host on our HP C Class blades, i see the following from dstat -f:
100 0 0 0 0 0: 0 0 95 5 0 0: 0 0 97 3 0 0: 0 0 99 1 0 0: 0 0 99 1 0 0: 0 0 100 0 0 0: 0 0 99 1 0 0: 0 0 99 1 0 0| 0 0 | 611k 654k| 0 0 |1462 30
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
Error: tick problem detected, this should never happen !
100 0 0 0 0 0: 0 0 95 5 0 0: 0 0 97 3 0 0: 0 0 99 1 0 0: 0 0 99 1 0 0: 0 0 100 0 0 0: 0 0 99 1 0 0: 0 0 99 1 0 0| 0 407k| 491k 540k| 0 0 |1328 36

Some relevant system info:
[root@enclosure103-blade01 ~]# uname -a
Linux enclosure103-blade01.mtc.ibsys.com 2.6.18-53.1.13.el5.xs4.1.0.254.273xen #1 SMP Tue Mar 4 17:55:32 EST 2008 i686 i686 i386 GNU/Linux
[root@enclosure103-blade01 ~]# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU E5335 @ 2.00GHz
stepping : 7
cpu MHz : 2000.070
cache size : 4096 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc up pni monitor ds_cpl vmx tm2 cx16 xtpr lahf_lm
bogomips : 4002.20

[root@enclosure103-blade01 ~]# cat /etc/redhat-release
XenServer release 4.1.0-7843p (xenenterprise)

Now, the blade actually has 2 quad core processors, but he xen dom0 only sees one of them (obviously)