http://bugs.winehq.org/show_bug.cgi?id=16061
--- Comment #8 from Jon Burgess jburgess777@googlemail.com 2008-11-17 17:23:15 --- I found the reason, I was running in Win98 mode. Once I switched to WinXP the test app got up to 2714MB. At this point I think the process hit the 4GB virtual size limit.
The cut down osm2pgsql utility now runs through the Finnish data set fine. It takes about twice as long as the native Linux version which I think is really pretty good.