Qt-4.6.0-beta1 on Linux Ubuntu 9.04 crashes for me when loading a grayscale TIFF image using e.g. this code:

#include <QApplication>
#include <QLabel>

int main( int argc, char **argv )
{
QApplication app( argc, argv );
QLabel *lab = new QLabel();
lab->setPixmap(QPixmap("test.tif"));
lab->show();
return app.exec();
}

The test image used is attached below.
The relevant line in the output from "configure" before compiling Qt-4-6-0-beta1 read:

TIFF support ........ plugin (system)

/usr/lib/libtiff.so.4.2.1 is installed in the system, but I don't think it causes the problem as I tried 5 other image viewers on the supplied image file and only Qt has a problem with it.
TIFFs in full color load OK with the above program, only grayscale TIFFs are affected.

Console output from the crash:

• • • glibc detected *** prog: free(): invalid next size (normal): 0x094b55c8 ***
      ======= Backtrace: =========
      /lib/tls/i686/cmov/libc.so.6[0xb6f4c604]
      /lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb6f4e5b6]
      /usr/local/Trolltech/Qt-4.6.0/lib/libQtGui.so.4(_ZN10QImageDataD1Ev+0xa9)[0xb76f2447]
      /usr/local/Trolltech/Qt-4.6.0/lib/libQtGui.so.4(_ZN6QImageD1Ev+0x70)[0xb76f26b8]
      /usr/local/Trolltech/Qt-4.6.0/lib/libQtGui.so.4(_ZN11QPixmapData8fromFileERK7QStringPKc6QFlagsIN2Qt19ImageConversionFlagEE+0x1d7)[0xb7721405]
      /usr/local/Trolltech/Qt-4.6.0/lib/libQtGui.so.4(_ZN7QPixmap4loadERK7QStringPKc6QFlagsIN2Qt19ImageConversionFlagEE+0x739)[0xb7719275]
      /usr/local/Trolltech/Qt-4.6.0/lib/libQtGui.so.4(_ZN7QPixmapC1ERK7QStringPKc6QFlagsIN2Qt19ImageConversionFlagEE+0x9c)[0xb7719be2]
      prog[0x8048b68]
      /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe5)[0xb6ef3775]
      prog[0x80489f1]
      ======= Memory map: ========
      08048000-08053000 r-xp 00000000 08:03 1282020 /home/drhex/src/q4test/prog
      08053000-08054000 r--p 0000a000 08:03 1282020 /home/drhex/src/q4test/prog
      08054000-08055000 rw-p 0000b000 08:03 1282020 /home/drhex/src/q4test/prog
      09447000-094cb000 rw-p 09447000 00:00 0 [heap]
      ...