Error: loop ends every second (solved)

[zarsoft]

When you press "1" the loop ends every second.

Code:

SUB Menu
DIM k$ AS STRING
CLS
PRINT
DO
  PRINT
  PRINT
  PRINT "MENU"
  PRINT " 1 - Test"
  PRINT " 0 - Exit"
  DO
    k$ = INKEY$
  LOOP UNTIL (k$ >= "0") AND (k$ <= "1") ' loop ends every second
  'LOOP UNTIL k$ <> "" ' runs OK
  'LOOP UNTIL (k$ = "0") OR (k$ = "1") ' runs OK
  'LOOP UNTIL (k$ >= "0") AND (k$ <= "1") ' loop ends every second
  PRINT
  IF k$ = "1" THEN PRINT "Option 1"
LOOP UNTIL k$ = "0"  
PRINT
PRINT
PRINT
END SUB

Menu