Some more info...
If I use the example with some commented lines (see bellow) I have compile errors:
doSleep = TRUE
// Box
DRAWRECT 0,0,32,32,RGB(255,255,255)
GRABSPRITE 0, 0,0,32,32
CLEARSCREEN
DRAWRECT 0,0,320,32,RGB(0,100,255)
GRABSPRITE 1, 0,0,320,32
CLEARSCREEN
b_InitWorld(0,0, 640,480, 0.0, 10.0, doSleep)
//LOCAL box1%, ground%
//box1 = b_CreateBox(1, .2, .5, 301,20,32,32)
//box2 = b_CreateBox(1, 3.2,.5, 347,20,32,32)
//cir1 = b_CreateCircle(1,1,.5, 290,-10,25)
//ground = b_CreateGroundbox(323,300,320,32)
//
//
//DEBUG "box1 "+box1+"\n"
//DEBUG "box2 "+box2+"\n"
//DEBUG "cir1 "+cir1+"\n"
//DEBUG "gnd "+ground+"\n"
//
//// a triangle
//LOCAL pts[]
//DIM pts[3][2]
// // polygon points (clockwise!!)
// // x y
// pts[0][0]=0; pts[0][1]=0
// pts[1][0]=20;pts[1][1]=15
// pts[2][0]=0; pts[2][1]=20
// b_CreatePoly( 1, 2.0, 0.5, 301,60, pts[])
//
//
//
//b_BodySetAngle(box1,47)
//
//b_BodySetAngle(box2,44)
WHILE TRUE
b_Update(0.1, 10)
// ROTOSPRITE 0, b_BodyGetPosX(box1)-16, b_BodyGetPosY(box1)-16, b_BodyGetAngle(box1)
// ROTOSPRITE 0, b_BodyGetPosX(box2)-16, b_BodyGetPosY(box2)-16, b_BodyGetAngle(box2)
// ROTOSPRITE 1, b_BodyGetPosX(ground)-160, b_BodyGetPosY(ground)-16, b_BodyGetAngle(ground)
b_WorldDebug() // debug a wireframe of what's happening
SHOWSCREEN
WEND
SUB GLB_ON_QUIT:
b_Cleanup()
ENDSUB
Really don't understand why. I only comment the drawing routines...