Does anybody know O'Haskell or Timber and its interface Tk.hs to Tcl/Tk (see here)?

I have the following problem:

Tk.hs contains a record (structure) Canvas with selectors

line      :: [(Int,Int)]      -> [LineOpt]      -> Request Line
polygon   :: [(Int,Int)]      -> [PolygonOpt]   -> Request Polygon

that are compiled into synonymous Tk widgets for lines and polygons, respectively. Unfortunately, Tk.hs crashes if the point list parameter of line or polygon 
contains more than 100 points. Why??? 

Of course, one may split a point list into smaller ones that are compiled correctly. But this may not produce the same picture, for instance, if the entire list 
represents a polygon to be filled or a line to be smoothened.

Peter