Claws-mail closes because another can't open?

I’ve noticed claws-mail suddenly decides to shut down. I’ve started it
from console and got the following messages before shut-down. The first
couple of lines appear dozens of times and are probably unrelated.


/home/graham/.claws-mail/newscache/ unlink: No such
file or
directory /home/graham/.claws-mail/newscache/
unlink: No such file or directory claws.c:102:Starting Claws Mail
version Claws Mail 3.9.3 utils.c:1906:using default
rc_dir /home/graham/.claws-mail main.c:2163:Using control
socket /tmp/claws-mail-1000/ca5d42c47df9fea238d06858b40ea873
main.c:2257:another Claws Mail instance is already running.

It seems weird that a new version is trying to startwhilst one is still

Graham P Davis, Bracknell, Berks.
openSUSE 12.3 (64-bit); KDE 4.12.0; AMD Phenom II X2 550 Processor;
Kernel: 3.7.10; Video: nVidia GeForce 210 (using nouveau driver);
Sound: ATI SBx00 Azalia (Intel HDA); Wireless: BCM4306