stopped processes using cpu?

[Dieter BSD]

8.2 on amd64
Top(1) with no arguments reports that some firefox processes are using cpu
dispite being stopped (via kill -stop pid) for at least several hours.
Adding -C doesn't change the numbers.  Ps(1) reports the same.
Interestingly, a firefox that isn't stopped is (correctly?) reported as
using 0 cpu.  The 100% idle should be correct, but who knows.

last pid: 51932;  load averages:  0.07, 0.99, 1.42 up 14+19:02:56  08:48:28
267 processes: 1 running, 138 sleeping, 128 stopped
CPU:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
Mem: 1665M Active, 653M Inact, 240M Wired, 95M Cache, 372M Buf, 815M Free
Swap: 8965M Total, 560K Used, 8965M Free

  PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
44188 a           9  44    0   303M   187M STOP   113:19 13.43% firefox-bin
92986 b          11  44    0   164M 62848K STOP     0:18  5.03% firefox-bin
16507 c          11  44    0   189M 88976K STOP     0:13  0.24% firefox-bin
 2265 root        1  44    0   248M   193M select 625:38  0.00% Xorg
51271 d          10  44    0   233M   128M ucond   12:12  0.00% firefox-bin