Spurious characters printed on terminal

[mirfatif]

When quitting from pypager, sometimes I see characters like these on terminal:

112;26M35;111;26M35;110;26M35;109;26M35;107;27M35;105;27M35;103;27M35;102;28M35;100;28M35;99;29M35;98;29M35;96;29M

^[[<35;56;35M^[[<35;56;

I cannot reproduce this. It happens randomly.

On Ubuntu using xfce4-terminal 0.8.10-1.