The problem of working at low speed

Bpinv

Hello.
I have the following problem.
I use ddcsv2.1 to control the laser.
When the cutting speed decreases, the laser starts working incorrectly. Problems begin at speeds below 1000 mm / min and increase with decreasing speed. Photo attached. On the direct parts of the work there is no problem. You can help?

Bpinv

The trajectory incorrect at low speed.
At high speeds everything works correctly.

Bpinv

In attache MNT /nand1-1/setting and nc code

Bpinv

thank. I will try.

Bpinv

How I can install the firmware?

Bpinv

Hello.
I reinstalled the software. Problem still exists. At high speed (F = 1500 mm/min) draws closed regular circles. At low speeds (F = 100 mm/min) , the laser path is irregular. For some reason, on the arcs the direction of movement of the laser changes and instead of a circle a strange figure is obtained. Draws straight lines correctly at any speed. I attach the photo again: work with the same nc-code at different speeds.