michiguel wrote:
I will certainly try to find out. Love and hate sometimes are indistinguishable

and maybe ChessGUI hates gaviota. Do you have the log files?
Miguel
Solution found !
With "log = off", all 4 games crashed.
With "log = on", all 4 games get played.
;=========================
; parameters for Gaviota
;=========================
;-------------------------------------------------------
; name that Winboard will use for saving games into pgn
;-------------------------------------------------------
name = "Gaviota 0.74"
;------------------------------------------------------------
; hashmem --> is hash tables (transposition, refutation).
; ref_table --> is a special table for refutation moves,
; keep it smaller than hashmem,
; probably half is best
; learn_table --> holds information from learn.epd
; do not set it bigger than 1 M
; pawn_table --> information about pawn structure.
; keep it small, 1-4 M
; M is Megabytes, k kilobytes , b bytes
;-------------------------------------------------------------
hashmem = 16 M
ref_table = 32 M
learn_table = 1 M
pawn_table = 4 M
;----------------------------------------------
; log info. max_logs is number of files kept.
; After that number is reached, it will start
; to overwrite them
;----------------------------------------------
log = on
max_logs = 2
;-----------------------------------------------------------------------
; ponder can have three values, 0, 1, or 2 (recommended).
; 2: Pondering will be determined by the interface (winboard, etc.)
; 1: Ponder is on, hardwired, no matter what the interface wants
; 0: Ponder is off, hardwired, won't turn on even if the interface wants
;-----------------------------------------------------------------------
ponder = 2
;-------------
; book info
;-------------
book = on
book_file = "cleanbook.bin"
book_learn = off
;------------------------------------------------
; learning of positions when is out of book.
; learn = on --> will save what just learned,
; use_learned = on --> will use any previous stored
; information in the "learn_file"
; learn_file = "/properpath/whatevername.epd"
;------------------------------------------------
learn = off
use_learned = on
learn_file = "learn.epd"
;-------------------------------------------------------------------
; won't show every output detail in the first n plies of the search
;-------------------------------------------------------------------
quiet_level = 6
;---------------------------------------------------------------------------
; logs when the node/sec is lower than "alert_nps"
; it is useful to detect when the program slowed down because of the OS etc.
;---------------------------------------------------------------------------
alert_nps = 10000
;-----------------------------------------------------------------
; Runs all the commands included in the file after initialization
; and before accepting commands from the user.
; Delete the command if you do not want to have an initial script
; or comment it out placing a semicolon before.
;-----------------------------------------------------------------
;script_file = "input.txt"
;-----------------------------
; Resign in hopeless position?
;-----------------------------
resign_mode = on
;------------------------------------------------------
; Should I kibitz info on computer tournaments online?
;------------------------------------------------------
kibitz = off
;---------------------------------
;
; Gaviota Tablebase parameters
;
;---------------------------------
use_tablebase = on
tb_probing_depth = 2
tb_pieces_used = 3
tb_cache = on
tb_cache_size = 16 M
tb_cache_slot_size = 8 k
tb_path_1 = "gtb"
tb_path_2 = ""
tb_path_3 = ""
tb_path_4 = ""
;-------------------------------------------------------------------
; SAN support (Standard Algebraic Notation) (e.g. Nf3)
; on ==> will try to send and accept SAN moves if GUI supports it
; off ==> will use default coordinate notation (e.g. g1f3)
;
; Some GUIs (Arena, ChessGUI etc.) are NOT fully SAN compliant
; and send wrong SAN moves. Use SAN = off with those GUIs
;-------------------------------------------------------------------
SAN = off
;------------------------------------------------------------
; PARALLEL SEARCH
; cores --> CPU Usage
; Gaviota will launch up a number of threads
; equal to this value
; Supported up to 16 cores
;------------------------------------------------------------
cores = 1
;-------
; end!
;-------