With the php-code widget, if I put in
<?php echo "Coming soon"; ?>
I get what I expect (those two words appearing in the sidebar in the right place).
If I edit a PHP file manually and serve it through php, and put in
<?php system("date"); ?>
I get what I expect (the current system date at that point in the page).
Back in the php-code widget, if I put that same exact code -- I can't save it. I click save, and it just sits there spinning the activity spinner forever. This repeats many times, and when I change the data back to something trivial the save suddenly works again.
This is the Dreamhost PHP install, with my own WordPress install running on it. PHP isn't running in safe mode, and as I say, that "system" function works in a manually-created php file.
Is there anything in widget content editing that might be blocking my save? And why isn't it giving me an error message if so? And how can I turn it off?