This my first post.
I am using ubuntu 11.10 64 bit on asus k53sv netbook.
Whenever I double click some large sized (>16 mb and some upto 450 mb) jpeg and png files, it makes my desktop to freeze completely.

I have tried to produce the bug (if can call it so) several times and here is what I noted just before it goes to freeze:

1. The physical memory usage suddenly increases from 500 mb to 5.2 GB just after opening in shotwell photo manager.
(I have 8 GB RAM in my machine.)
2. CPU usage shown in 'System Monitor' is about 100% in two of the eight CPUs shown there. (Its an Intel core i7 2670QM, 2.2 GHz)
3. When try to zoom the image with mouse (or whether by hitting ctrl+1 key combination, doesn't matter), the RAM usage suddenly increases to 7.3 GB and then simultaneously see 4 of the CPUs loaded to 100%.
4. It just freezes within a second or two after that. Nothing works on keyboard, nor the mouse. All freezes. Try ctrl+alt+F1, not working. Power consumption just booms from 13 W to 47 W just after trying for zoom.
5. I left the machine for around 5-15 minutes in the frozen state, waited for it to respond, and each time I had to hard reset finally.
6. The machine goes to cool state (fan noise calms down, heating of machine lowers to usual level) after 3-4 minutes of commence of freezing.
7. I did dmesg on reboot to find a thing:
[   31.281228] init: plymouth-stop pre-start process (1848) terminated with status 1
The same files open so smoothly in EyeOfGnome (eog). Even eog takes much less of cpu (loads only 1 core to 100% for a short time) and less RAM (3.5GB) while it is open and remains constant at 3.5GB while zooming.
What can be wrong, I have produced the same bug in both "gnome 3" and "unity" sessions in the same machine (USUALLY I USE GNOME 3). Unity is used rarely. I have home folder encrypted.