The following is reported immediately when attempting to run a sketch in dual
monitor setup:
#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x03349a2a, pid=204,
tid=264
#
# Java VM: Java HotSpot(TM) Client VM (1.4.2_12-b03 mixed mode)
# Problematic frame:
# C [awt.dll+0x69a2a]
#
# An error report file with more information is saved as hs_err_pid204.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

Error ONLY occurs when the "Extend my Windows desktop onto this monitor" is
checked in a "wide-dual" configuration. Uncheck that option, disable the second
monitor, and sketch runs fine. (note: I'm not trying to actually DO anything fancy
with that second monitor via Processing, the entire IDE is on the first monitor, but the
mere presence of that second monitor seems to be the problem)

I thought at first it was an OpenGL thing, since that's what I was working on, but it
occurs wtih JAVA2D and P3D renderers also. Doesn't seem to be sketch or renderer
related (can be duplicated with example sketches, "Pointilize" for example was
tested)

as of Beta 0125, 0132, 0134 (and probably others, but i have those readily available
to test) using provided JRE in all cases.
WinXPsp2 w/ all latest patches
ATI Radeon x600 256M 1280x1024

edit]
java error log

hm, that looks like a jdk bug. try using with a more recent version of java
(e.g. install java 1.6 and rename the folder in your java install to
something else temporarily so that it'll use the installed 1.6).

you can also try running FSEM examples with that version of 1.4.2, but my
guess is that that version of java doesn't get along well w/ your video
card drivers.

Confirmed - already have 1.6.0_03 installed, so just renamed P5's java folder, and
everything ran fine with dual monitor setup. (but boyyy is 1.6 slower than 1.4!!)
Thanks for your time, go ahead and close.

bummer, i was starting to warm up to 1.6 as they seemed to be getting the
kinks out and supposedly it's faster. oh well... :-/