Hi Justin, and anyone else interested...
OK... I was able to get the new version of Poodll drawings to work. The final hurdle or problem had to do with file permissions.
To find the error, I looked in the Apache error log file. This file is separate from the error logs in the Moodle directory. On my hostmonster account, the error log is in
/usr/local/apache/logs/error_log
The file contained errors like this:
SoftException in Application.cpp:256: File "/home/halverph/public_html/moodle/filter/poodll/poodllfilelib.php" is writeable by group, referer: http://www.halverscience.net/moodle/mod/quiz/attempt.php
I fixed the problem by changing all the Poodll files' permissions from 775 to 755
and also all the Poodll directories permissions from 664 to 644
The unix shell commands to do this were to go into the public_html/moodle directory and entered these commands. (Caution! Make sure you have a good backup first.)
[halverph@server moodle]$ find . -type d -exec chmod 755 {} +
[halverph@server moodle]$ find . -type f -execdir chmod 644 {} +
That got things working.
This permissions problem has come up before, when installing the STACK question type. I think it happens because some web servers are more fussy than others with regard to permissions and other factors related to security. I guess Hostmonster is being super-careful.
Now my students can enjoy drawing graphs!
Thanks...
Peter H.