Null Rows with pt-table-sync

[Hiraedd]

Hi all,

I'm using pt-table-sync to sync a table between two servers.

The source is a server that is acting as slave in a cluster, the destination is a standalone server.

When syncing a specific table with about 50M rows, I get a set of empty rows

at the end of the dest table. Only the id field is not null, while 

all other fields are null. 

If I use the --print option, I can see the null rows:

...

INSERT INTO `db`.`table`() VALUES () /*percona-toolkit ... lock:0 transaction:1 changing_src:0 replicate:0 bidirectional:0 ...*/; 

...

The number varies, but is around a few hundreds.

These rows appear always at the end of the table. I tried to modify the chunk-size, but so far no success.

Any idea why I get these rows and how to avoid them?

TIA

M.