Error when performing heavy queries (pentaho) (no replies)

Hi. When I perform hard queries in pentaho, the following occurs:
< 60 sec: mysql executes the query, pentaho displays query execution
after 60 sec: mysql executes the query, pentaho does not displays query execution
I tried to change the following parameters of mysql jdbc-connection:
netTimeoutForStreamingResults = 600
enableQueryTimeouts = false
And in mysql parameter:
net_write_timeout = 600
But nothing changes.
OS: Windows 7