Error in CONDITIONS::CLCS-UNIVERSAL-ERROR-HANDLER [or a callee]: Couldn't protect



I've tried Maxima on a machine with Ubuntu 8.10. Everything was 
installed from the standard repository; it's 5.13.0 and GCL 2.6.8.

While doing different things (loading a /share/contrib package or 
calculating something), Maxima may say

  Maxima encountered a Lisp error:

  Error in CONDITIONS::CLCS-UNIVERSAL-ERROR-HANDLER [or a callee]:
    Couldn't protect

  Automatically continuing.
  To reenable the Lisp debugger set *debugger-hook* to nil.

After that it may exit with segfault.

Does anybody know why it happens? Is it because of broken package(s)?
A simple test case for Ubuntu users: run maxima and say

  load ("simplify_sum");

(Generally, I'm using the cvs version with sbcl and everything is OK.)

-- 
Boomtime, Aftermath 20 YOLD 3174
Alexey Beshenov  http://beshenov.ru/