I think wikipedia has the initial state wrong, or you have copied it incorrectly. Here is an alternative starting state I found on the web.
Const px=10,py=10 Data "Gospers Glider Gun",0,2,0,3,1,2,1,3,8,3,8,4,9,2,9,4,10,2,10,3,16,4,16,5,16,6,17,4,18,5,22,1,22,2,23,0,23,2 Data 24,0,24,1,24,12,24,13,25,12,25,14,26,12,34,0,34,1,35,0,35,1,35,7,35,8,35,9,36,7,37,8,-1,-1 Read pat$,x,y While x>=0 pixel(px+x,py+y)=1 Read x,y Wend