Stopping text from flowing around sidefloats

[Fabio Fogliuzzi <fogliuzzi@libero.it>]

I'm a newbie in Context (and TeX) typesetting, but I'm seriously   
thinking of switching  from my current wokflow, FrameMaker based, to a  
new one based on this system, impressive for its quality and  
flexibility.
The main work at my office is the producing of  technical manuals  
(250-500 pages) for megayachts, covering the entire workflow (layout,  
technical writing, illustrations etc.).
My first attempt in the use of  ConText was the finding of a way to  
mimic the basic layout currently used in Framemaker and the mode in  
which illustrations are currently placed in the manuals.
The basic layout in Framemaker is composed of a main text flow in which  
a column is reserved for placing side notes (warning notes, danger  
notes etc.) and a second column is reserved for the main text.

|------------------|----------------------------------------------|
|                        |                                               
                 |
|  Side Notes  |                       Main Text                     |
|                        |                                               
                 |
|                        |                                               
                 |
|------------------|-----------------------------------------------|

Normally the figures are placed in the main text area. In this case  
(depending from the width of the illustration) flows or doesn't the  
main text  flow around the illustration.
The larger figures however occupy all the width of the text flow ('Side  
Notes'+'Main Text') and the main text get interrupted by the  
illustration.

I replicated the basic layout  (the original layout is double sided but  
i don't care of this at this moment) with the following commands:

   \setuppapersize[A4][A4]
    \setuplayout  
[backspace=7.3cm,width=11.7cm,topspace=1.5cm,leftmargin=4cm,
      
rightmargin=0cm,leftmargindistance=0.8cm,height=27.2cm,header=2cm,footer 
=2cm,location=singlesided,marking=on]


The last command set the left margin,  and should replicate the 'Side  
Notes' column of the original layout.
With this setup there is no problem in placing figures smaller than the  
main text area.
For placing the larger figures I followed an example taken from page 29  
of the manual 'IT'S IN THE DETAILS' writing the following commands:

     \definefloat [largefigure][figure]
     \setupfloat [largefigure]  
[leftmargindistance=-\leftmargintotal,default={left,none,noident}]
     \useexternalfigure [provafigura] [Largefigure.pdf][width=16.5cm]
     ..........
     \placelargefigure [left] {ProvaFigura}  
{\externalfigure[provafigura]}

The last command work as expected for figure placement but cause the  
text of the paragraph immediately following the \placefigure command to  
flow around the placed figure in a tiny column (around 1cm in width)   
at the right of the page and outside the main text flow.

|------------------|----------------------------------------------|-a-
|                        |                                               
                 |-b-
| <---------------Large Figure ---------------------------->|-c-   
<----paragraph flowing outside the main text flow.
|                        |                                               
                 |-d-
|------------------|-----------------------------------------------|-e-

What is wrong? There is a way to prevent the text from flowing around  
sidefloats or a workaround to place large figures in the desired way?

Thank you in advance and Best Regards
F.Fogliuzzi.