Bizarre error after modifying any PHP code

Our PHP app which now includes LiveUser has started exhibiting a most  
peculiar error.

Often, but not always, after modifying *any* PHP code (could have  
nothing to do with our use of LiveUser), we will see this error:

init failed
array(1) { [0]=> &array(7) { ["code"]=> int(-1) ["params"]=> array(1)  
{ ["msg"]=> string(39) "Could not instanciate storage container" }  
["package"]=> string(8) "LiveUser" ["level"]=> string(9)  
"exception" ["time"]=> float(1126812538.0584) ["context"]=> array(4)  
{ ["file"]=> string(43) "/usr/local/lib/php/LiveUser/Perm/ 
Simple.php" ["line"]=> int(156) ["function"]=> string(4)  
"init" ["class"]=> string(21) "LiveUser_Perm_Complex" } ["message"]=>  
string(13) "Unknown error" } }

If I just reload the page, the error goes away until I modify some  
code again.

The problem is probably LU-related, but I've no idea what it might be.