QFileDialog hangs on Solaris 10 with gcc 4.x, Sun CC 5.10

Steps to reproduce / test case:

Build Qt 4.6.0-tp1 on Solaris 10 using gcc 4.x (4.3.3, 4.4.0 tested) or Sun CC 5.10 (Sun Studio 12)

Run examples/dialogs/standarddialogs/standarddialogs

Try any of the QFileDialog methodss, e.g. QFileDialog::getOpenFileName

Bug: The standarddialogs program will hang rather than displaying the QFileDialog.

More information:

This QFileDialog hanging bug is specific to the combination of Solaris 10 and a recent gcc or Sun CC compiler (gcc 4.3.3, gcc 4.4.0, Sun CC 5.10 all fail). The bug also exists in Qt 4.5.2 in addition to Qt 4.6.0-tp1.

However,
If Qt is built on Solaris 10 with gcc 3.4.6 (i.e. older version) then QFileDialog works OK.
If Qt is built on Solaris 8 (i.e, older version) with gcc 4.4.0 then QFileDialog works OK.

It's only the combination of Solaris 10 and gcc4 or Sun CC 5.10 that causes QFileDialog to hang.