Brandon, Thank you for helping me along here!
Here is the output of "ldd Mathematica": linux-gate.so.1 => (0xb8042000) libm.so.6 => /lib/libm.so.6 (0xb800c000) libpthread.so.0 => /lib/libpthread.so.0 (0xb7ff4000) librt.so.1 => /lib/librt.so.1 (0xb7feb000) libXt.so.6 => /usr/lib/libXt.so.6 (0xb7f9a000) libXext.so.6 => /usr/lib/libXext.so.6 (0xb7f8b000) libXmu.so.6 => /usr/lib/libXmu.so.6 (0xb7f74000) libSM.so.6 => /usr/lib/libSM.so.6 (0xb7f6a000) libICE.so.6 => /usr/lib/libICE.so.6 (0xb7f51000) libX11.so.6 => /usr/lib/libX11.so.6 (0xb7e3a000) libc.so.6 => /lib/libc.so.6 (0xb7cf7000) /lib/ld-linux.so.2 (0xb8043000) libuuid.so.1 => /lib/libuuid.so.1 (0xb7cf2000) libxcb.so.1 => /usr/lib/libxcb.so.1 (0xb7cd7000) libXau.so.6 => /usr/lib/libXau.so.6 (0xb7cd3000) libXdmcp.so.6 => /usr/lib/libXdmcp.so.6 (0xb7ccd000) libdl.so.2 => /lib/libdl.so.2 (0xb7cc9000) So far, I see a bunch of references Java directories in the installation and a few .jar files. I haven't seen any reference to Qt. I did see the GUI-Kit and JLink in the AddOns directory. Basically, the only thing that triggers the crash is if I hold down the mouse button and drag the scrollbar UP right after I drag it DOWN. Dragging it down doesn't seem to make any difference by itself and hasn't crashed the program until I reverse and drag UP. Sometimes going up slowly will be OK too, but if I drag UP rapidly, it will crash. I can use the scroll arrows on top and bottom of the scrollbar, and it will scroll without incident, albeit slowly. Can the integrity of the above library links be checked, or would rebuilding all of them again make any difference? What is the command to determine which package the given .so.* file belongs to? Many thanks, Denis