"strange closure type 37108": MSWin32, 6.4.1 snapshot and other versions

In compiling pugs, usually at Pugs.AST.Internals or Pugs.Parser (large
files), I get GHC crashes. The error is typically "strange closure type
37108" but other numbers also appear (0 sometimes).

I tried this with:

An oldish GHC 6.5 snapshot
GHC 6.4 release
Latest GHC 6.4.1

My system is an x86 with plenty of RAM running Windows XP. I'm setting
-M450m for the compilation: up till recently, as 350m was enough so this
ought to be sufficient.

Is there anything I can do to give you more information? Or to work around
this problem? My own pugs development is stalled because of this :-(

Thanks muchly,
Gaal

-- 
Gaal Yahas <gaal@xxxxxxxxxx>
http://gaal.livejournal.com/