Comment 4 for bug 1178024

The reports of Synaptic 0.80~exp2 freezing seem to be consistent for Ubuntu Raring and Linux Mint 15 RC although it appears that not all users are experiencing the freeze. What is not consistent is the reason for the freeze although there is more than one report stating that the the searching for and/or installing packages causes Synaptic to freeze hard. A couple other reports state that the freeze occurs when scrolling through search results using the keyboard arrow keys but not with a touch pad or mouse scroll wheel. This is what causes the freeze for me and I can duplicate it successfully.

Starting Synaptic (successfully) from the terminal using the command "gksu synaptic", doing a "Quick search" and scrolling back and forth through the search results using the arrow keys freezes Synaptic hard and gives me this in the terminal repeatedly (repeats about every second or two):

"widget == NULL with: label_source"

I have to forcibly quit Synaptic but this does not return the command prompt to the terminal which keeps repeating "widget == NULL with: label_source". I have to CTRL+C to return the terminal to the command prompt. If I try restart to restart Synaptic via the terminal it fails with this:

"Another synaptic is running. Trying to bring it to the foreground"

Yet under "Processes" tab of "System Monitor", no Synaptic process is shown. Entering "sudo killall synaptic" in the terminal apparently kills this wayward synaptic process and I can restart Synaptic successfully. Doing the same Quick search and scrolling through the search results using the scroll wheel of the mouse and the touch pad of my laptop (ThinkPad R61) does not reproduce the freeze while scrolling with the arrow keys does.

The key difference here is that scrolling through the packages with the arrow keys highlights each package in sequence while scrolling with the mouse wheel of touch pad does not.

Hope this info helps.