Ventus 2C manual typo?

Any V2C drivers out there --

I'm reading the "Use of wing flaps" section of my V2C manual and there
is a table (page 4.5.3.3) with flap settings (L, +2/+1, -1, -1, -2, S,
S1) in the second column and speeds to fly for various gross weights in
columns to the right.

The first column is the "Use of flaps for" description. The row that
begins with "Best L/D" also has "-1" for the flap setting.

I hate to make assumptions, but can I assume that should be "0"?

It will be a lot of fun when I pick the glider up this Saturday to find
it has two "-1" settings and no "0"

2NO
304CZ^H^H^H^H^HVentus 2C

Greetings:

For the last five years, and until very recently I owned Ventus 2c
serial number 51. A friend owned a Ventus 2c with a serial number in
the low thirties. His owner's manual says best L/D is obtained with
a flap setting of 0. My owner's manual says best L/D is obtained
with a flap setting of -1. In comparing the two manuals, as best as
I can remember, it did not appear that the difference was attributable
to a "typo". My sense, (i.e., only a guess) was that Schempp-Hirth
did some additional testing and updated their owner's manual to
reflect new flight test findings.

John O. Graybill