jde-jdb problem

I use jde-jdb to debug.
The jdb output looks like:
Step completed: "thread=Thread-22", xxxx.xxxx.xxx(), line=733 bci=124
and jde-db-jdb-1-4 can parse it correctly.

(defmethod initialize-instance ((this jde-db-jdb-1-4) &rest fields)
  "Constructor for jdb-1.4."
  (call-next-method)
  ;; Regular expression used to find a jdb breakpoint position marker.
  ;; The regular expression has two subexpressions. The first matches
  ;; the name of the class in which the breakpoint occurs; the second, the
  ;; line number at which the breakpoint occurs."
  (oset (oref this bp-listener)
   :marker-regexp
   "^.*: \"thread=.*\", \\(\\(.*[.]\\)*\\)\\([^$]*\\)\\($.*\\)*[.].+(),
line=\\([0-9,.]*\\)"))

But sometimes(a ratio of about 5%),jdb output looks like:
Step completed: Thread-22[1] "thread=Thread-22", xxxx.xxxx.xxx(), line=735
bci=133

And jde-db-jdb-1-4 can't  parse it correctly,
so it stop working.

I modify form "^.*: \"thread=.*\" -> "^.*: .*?\"thread=.*\",and
It works corretly,But  I don't know the reason.

Anybody know why?
where there is a <Thread-22[1] > between <Step completed: >
and <"thread=Thread-22", xxxx.xxxx.xxx(), line=735 bci=133>

My platform is winxp,emacs22,sun jdk 1.5,cedet 1.0pre4.