This code only show the sprite after the sync for me.
sync on : sync
create bitmap 1,100,100
box 0,0,50,50 : box 50,50,100,100
get image 1,0,0,100,100,1
delete bitmap 1
sprite 1,0,0,1
wait 250
sprite 1,100,100,1
wait 250
sprite 1,250,250,1
wait 250
i as integer
i = 110
stretch sprite 1,i,i : inc i,20
wait 250
stretch sprite 1,i,i : inc i,20
wait 250
stretch sprite 1,i,i : inc i,20
wait 250
stretch sprite 1,i,i : inc i,20
wait 250
stretch sprite 1,i,i : inc i,20
text 0,0,"text"
sync
wait key
dbpro : p166mmx @ 233 : 256mb : sb 128pci : sis onboard