What normally causes "GC missed a reference"?

[Rob Browning]

We've got a problem in gnucash using the latest g-wrap with
guile-1.3.4 (we have to keep supporting 1.3.4 for now b/c it's very
common -- RedHat 6.? uses it and as I understand RedHat doesn't
version the libs so it's hard to install 1.4 in parallel...).

Anyway here is the most typical error message, but they can vary.  I
was hoping someone might know the most likely cause so I can narrow my
search.  Also any ideas about the easiest way to track this down would
be welcome.

  /opt/gnucash/share/gnucash/scm/report.scm:56:18: In procedure 
gnc:report-window in expression (gnc:report-window rept):
  /opt/gnucash/share/gnucash/scm/report.scm:56:18: Wrong type argument in 
position 2: #<freed cell 0x40d6d158; GC missed a reference>

Thanks

-- 
Rob Browning <address@hidden> PGP=E80E0D04F521A094 532B97F5D64E3930