Printer breaks alot

Blisk

When printing from repetier printer pauses alot for a bit of second, that makes blobbing and printed item is really bad printed out.
When printing directly from SD card on printer than it is ok.
Where can be problem??
I have Prusa I3 printer with GT2560 board and latest repetier and windows 7.

Repetier

Check log file. If you have wrong baudrate or for any other reason a lot of communication errors that might slow down communication. Also many small segments in a row can be a problem. You might test Repetier-Server for communication. There communication is a bit faster. Also cpu intensive tasks on windows can cause pauses.

A even better solution is Repetier-Server on a Raspberry Pi 3 so you have no other software disturbing print and can access from everywhere in your intranet.

Blisk

Ok I have enabled log but it is not created in folder where it should be so I copied log at bottom of windows.
Baud rate is setted as it should be. CPU is not even at 35%. I will test also server

Here is a log
10:02:08.174 : Error:No Line Number with checksum, Last Line: 26469
10:02:08.174 : Error:Line Number is not Last Line Number+1, Last Line: 26469
10:02:08.174 : Resend: 26470
10:02:10.483 : Error:checksum mismatch, Last Line: 26474
10:02:10.483 : Resend: 26475
11:51:06.345 : Resend: 29605
11:51:06.361 : Error:No Line Number with checksum, Last Line: 29604
11:51:06.361 : Error:Line Number is not Last Line Number+1, Last Line: 29604
11:51:06.361 : Resend: 29605
11:51:06.891 : Error:Line Number is not Last Line Number+1, Last Line: 29647
11:51:06.891 : Resend: 29648