I had many problem and brain damage because I used MPASM as assembler instead of PM.EXE (I used MicroCode Studio too). Simply line like
Code:
@ device  pic16F628, intrc_osc_noclkout
gave me strange error codes...
But now, the project is working. I hope somebody find it useful.
Thanks all of you for help.

Code:
'************************************************* ********
' LED FLASHING PROGRAM
' ======================
' PIC16F628 20I/P
' Pic Basic Pro Compiler 2.45, (c) 1998, 2004 microEngineering Labs, Inc.
' Assembler used is PM.EXE, provided with microEngineering Labs PICBasic Compiler
'
' This program flashes an LED connected to port RB0 of PORTB. The
' LED is flashed with 1 second intervals.
'************************************************* ************
'
INCLUDE "modedefs.bas"
'
@ device  pic16F628, intrc_osc_noclkout; Use internal oscilator
@ DEVICE pic16F628, MCLR_OFF ; Turn off internal reset (default) and leave RA.5 as an input
'
DEFINE OSC 4             ' Default Osc freq
CMCON     = 7          ' PortA = digital I/O
VRCON     = 0          ' A/D Voltage reference disabled
TRISB     = %00000000  ' PORTB all pins outputs
'
' Define RB0 as LED (pin number 6):
LED VAR PORTB.0 
' VSS - pin number 5  (Ground)
' VDD - pin number 14 (+5V)
' MCLR (pin number 4) pulled-up to VDD by 4.7Ko resistor 
'
'program start
AGAIN:
    LED = 1 ' Turn ON LED
    PAUSE 1000 ' Wait 1 second
    LED = 0 ' Turn OFF LED
    PAUSE 1000 ' Wait 1 second
    GOTO AGAIN ' Repeat forever
END ' End of program