You should report this to the game developer also.
I wrote to a developer. But while I was waiting for his reply, there was a Steam Update. And now it seams working =)
As I understood Matthew (the developer), it was a Steam problem.
I asked my friend, who had the same problem and now everything is alright.
Nothing extracted yet.
After exiting from the game it continue working in background.
There are two processes:
Workaround is only kill this process.
If it is needed, there is my sysinfo