Thank you Dave for your answer.

The fact is that I am a litlle lost with this LAT register!

I have a blinking led connected to portA.5 and with 18f2620 I used the alias : Led var portA.5, then the instroction

Led = !led made the led blinking.

Now with 18f26k20 this instruction doesn't work anymore but also LATA.5 = !LATA.5 doesn't work

Am I using the instruction the wrong way? Using the alias will it work?

Alberto