Is there any more info on this bug? Is it still in 3.0.12?
Is there a reproducable test case? Anything? :)

Setting as Analyzed until more info is available.

I will look into this more tomorrow. Here is the reply from the reporter.

Oops, should have updated or closed this one I guess.

The problem is with serialized strings. If the actual length of the
string is different than expected, as in the following case,
unserialize() returns false. 

s:9:"O'Reilly";

This can happen when magic quotes is turned on. If for example, you
were to read a string in from a file, serialize it, and store it in a
database, there is no way to then unserialize it:

file contents:                          O'Reilly
retrieved from file:            O\'Reilly
serialized:                                     s:9:"O\'Reilly";
stored in db:                           s:9:\"O\'Reilly\";
after stripslashes():           s:9:"O'Reilly";

If you pass the magic-quoted value to serialize, it will choke on the
escaped double quotes. If you run it through stripslashes(),
unserialize will choke on the string-too-short problem. You could maybe
work around it via regex, but...

I worked around it by turning off magic_quotes. Perhaps this is more of
a gotcha than a bug, but it would be nice to make unserialize smart
enough to deal with the possibility.