[GRASSLIST:3936] mysql: Cannot open select cursor

[ivan marchesini]

Dear users...
I'm working on a debian testing....and grass57 

I have got a problem: 
I connected grass57 with mysql:

db.connect driver=mysql database=tezio -p

and after I connected vector attribute to the same db:

v.database driver=mysql database=tezio -p

after this, I started v.digit and I created a new table using "settings
-> table"

the table was succesfully created!!!

later, I started to digitize. When I stopped a window appeared saying:

New record was created.
Cannot open select cursor:
'select * from sentieri where cat = 1'
on database 'tezio' by driver 'mysql'

and on the v.digit panel I obtained this:

dbmi: Protocol error
WARNING: Cannot open select cursor

I'm doing something wrong????

thank you very much for your attention!!!!

Ivan