From Brent Minder, who will not divulge how long it took to track this one down:

Hey Guys,

Just wanted to let you know about a symptom when running a large Stylevision report that blows up with a meaningless list of paragraph overflow warnings. This error occurs when the java virtual machine exceeds its maximum heap space allotment. You can increase the heap space in the fop.bat file like so:

Look in C:\Program Files\Altova\FOP-0.95\ (or C:\Program Files\Apache Group\FOP-0.94\)

Open fop.bat and modify line 72 from:

set JAVAOPTS=-Denv.windir=%WINDIR%

to something like this:

set JAVAOPTS=-Denv.windir=%WINDIR% -Xmx768m

Here is more detail on the error:

http://xmlgraphics.apache.org/fop/0.95/running.html#memory