DOCUMENT:Q168748    [winnt]
TITLE: Java Applets Cause IE 3.02 to Stop Responding w/ SP3
PRODUCT: Microsoft Windows NT
PROD/VER:4.00
OPER/SYS:WINDOWS
KEYWORDS:kbbug4.00 kbfile kbfix4.00

-------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Windows NT Workstation version 4.0
 - Microsoft Windows NT Server version 4.0
 - Microsoft Internet Explorer version 3.02
-------------------------------------------------------------------------

SYMPTOMS
========

Internet Explorer version 3.02 may hang when connecting to a Web link that
contains a Java application after you have installed Windows NT version 4.0
Service Pack 3. The application will stop responding only if the Display
Properties Color Palette is set to True Color.

CAUSE
=====

In Windows NT version 4.0 Service Pack 3 the GetDIBits API does not fill
the bit fields when a BI_RGB (uncompressed) DIB is returned on a True Color
(32 bpp) display. This GDI change was made because the bit fields are not
required in this case. As a side effect, this change may cause a regression
in applications that expect a valid RGB mask on a True Color display.

The Java virtual machine included with Internet Explorer 3.02 calls
GetDIBits when initializing the display palette. The Java virtual machine
expects a valid, signed RGB mask value larger than 0x80h and, if a value
less than 0x80h is received, it doubles the mask value in a tight loop
until it is larger than 0x80h. Because Service Pack 3 GetDIBits do not fill
the bit fields when a BI_RGB is returned, applications that evaluate the
RGB mask receive an unlikely result that can be negative (for example,
0xffffffe0h.) When the Java virtual machine evaluates the RGB mask and
receives a negative value, it loops forever and causes Internet Explorer to
stop responding.

It is important to note that the Java virtual machine should be treating
the RGB Mask as an unsigned integer. There are some conditions where an ATI
video card returns a valid RGB Mask value of 0xff000000h causing the Java
virtual machine to loop forever because it is not treating the mask as an
unsigned integer. A separate fix for the Java virtual machine issue with
ATI video cards in True Color will be available in Internet Explorer 4.0.
The Java code is licensed from Sun Microsystems, Inc.

RESOLUTION
==========

To work around this problem, do not use the True Color palette in Display
Properties.

Win32k.sys was modified to return a valid RGB color mask on True Color
display systems.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 4.0. A
supported fix is now available, but is not fully regression-tested and
should be applied only to systems experiencing this specific problem.
Unless you are severely impacted by this specific problem, Microsoft
recommends that you wait for the next Service Pack that contains this fix.
Contact Microsoft Product Support Services for more information.

The fix is also available for download on the Internet at the following
URL:

   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/chp/nt40/
   hotfixes-postSP3/java-fix

Additional query words: 4.00 ie 3.02 prodnt

============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.