[STUMP] crashing on startup

[Paddy Mullen]

I am relatively new to lisp and stumpwm but I have liked it so far.

After getting my setup honed, I hadn't restarted in about a week, yesterday I had to restart stumpwm for another reason, I now cannot restart it.

I removed everything from my stumpwm.start
everything except debugging info from my .stumpwmrc


(in-package :stumpwm)
(setf *debug-level* 20)
(redirect-all-output (data-dir-file "debug-output" "txt"))


I get the following error in debug-output.txt
line 8510:39:55 Outputting a message:
        ^2*Welcome to The ^BStump^b ^BW^bindow ^BM^banager!
        Press ^5*C-t ?^2* for help.
10:39:55 Window #<XLIB:WINDOW :0 400009> is dock-type. Placing in mode-line.

debugger invoked on a TYPE-ERROR in thread #<THREAD "initial thread" RUNNING {100371F9E1}>:
  The value 525/2 is not of type (UNSIGNED-BYTE 29).

I am running ubuntu 910, sbcl 1.0.29.11, on a lenovo t500 in 64 bit mode

what other information would be helpful to debug this problem?