[PD-dev] external weirdness only on windows

[Lorenzo]

Ok so, whilst keeping in mind IOhannes advice about getting into C 
externals, I had a go at writing my simple 'maths' external in C.
Everything seems to work fine and I created a test patch... but *only on 
windows* if I re-open the saved test patch (which has 3 numberboxes 
connected to 3 inlets, and a numberbox connected to the outlet) the 
object box (I mean the gray "thing") is disappeared and only a text like 
a comment is there (I can even drag it around).
If I recreate the object and attach the numberboxes again everything is 
fine.
If the object is without anything attached everything is fine.
In linux everything is fine...

Could it have something to do with the DLL I'm linking or is this some 
hidden mistake in the external code?

Clues appreciated.

Lorenzo.
PS: I'm using 0.42-5-extended.