[Rt-devel] spurious error being presented to users

[Olly Stephens]

On our production system, we are occasionally getting the following
error presented to users on the web page:

Can't use string ("RT::User") as a HASH ref while "strict refs" in use
at /opt/perl/lib/site_perl/5.8.8/DBIx/SearchBuilder/Record.pm line 389.

It appears to be sporadic, perhaps load related.  It typically happens
when someone replies to a ticket (so in Ticket/Update.html) but not
always. I can't - of course - reproduce it in our dev/test environment.

Does anyone know

a) What might be causing it (I know what the error means from a Perl
POV, I just don't know why it is happening occasionally; perhaps it's
caused by an RT::User object that isn't being properly checked for
initialisation before being used?)
b) Why it's being dumped to the screen instead of the log (because of
this, I'm not sure how to catch it to get a stack trace)

Thanks in advance,

Olly