There is an inconsistency in their counting, it seems.
While the summer 2007 patch is labelled as 11th patch on their news site, it is called patch 1.0.12 on their download site. A patch 1.0.01 is not listed under downloads, so there is the missing one.
Judging by the dates alone, a new patch is planned early 2008 (I gave a head up on it in the "other games" forum and called it 12th patch myself there, so Subman is forgiven), but their homepage so far does not list it for downloads. It will be 1.0.12, and will be the 11th patch indeed.
As long as I did not get it totally wrong and confused.