[Qt-interest] Strange crash on OSX

[Info]

Hi,

I'm experiencing a strange crash on OSX which does not occur on  
Windows and I can't see a logical reason for it, the line in question  
is:

QString message(QString("%1 %2").arg(err- 
 >time().toString(Qt::SystemLocaleShortDate)).arg(err->detail()));

Where err is a pointer to an object with a QDateTime and a QString and  
the error I receive is:

EXC_BAD_ACCESS (Sometimes with Non-aligned pointer being freed)

Now, I'm not freeing a pointer at this point but something must be,  
the stack trace up to the error is:

#0	0x909ae3e5 in tiny_malloc_from_free_list
#1	0x909a71cd in szone_malloc
#2	0x909a70d8 in malloc_zone_malloc
#3	0x909a706c in malloc
#4	0x92d979be in icu::Calendar::createInstance
#5	0x92da1abd in icu::SimpleDateFormat::initializeCalendar
#6	0x92da171b in icu::SimpleDateFormat::construct
#7	0x92da1673 in icu::SimpleDateFormat::SimpleDateFormat
#8	0x92da157f in icu::DateFormat::create
#9	0x92da13bf in udat_open
#10	0x941b5afe in CFDateFormatterCreate
#11	0x003384f8 in QSystemLocale::query
#12	0x00336fa1 in QLocale::toString
#13	0x00312d2e in QTime::toString
#14	0x00316e3f in QDateTime::toString

So it seems the error is in the QDateTime::toString() but I'm sure  
that it's something I'm doing that's causing it as I would have seen  
the problem before, I just can't figure out exactly what it is. Does  
anyone have any ideas?

I'm getting a lot of strange errors like this lately which don't occur  
in Windows and didn't occur until I started using XCode to build the  
project so I am certain it must be a compiler or linker setting  
somewhere which may be causing the problem but I'm not sure how to  
diagnose it. Sometimes the app will run for hours, sometimes only  
seconds. The error above is the most common but I get similar errors  
elsewhere.

Any help in tracking down the problem would be greatly appreciated!

Thanks.