Problem with posn-at-point

[LaserDoodads Info]

With the cursor in column 10 or greater on any line of text and no horizontal 
scrolling in effect

M-: (car (nth 6 (posn-at-point))) <ret>

I get the value I expect.  That is, (current-column).

Now do 
M-: (scroll-left)
M-: (car (nth 6 (posn-at-point))) <ret>

The position returned is (- (current-column) 10).
Very strange considering (window-hscroll) is 105 at the moment.

If (current-column) is less than 10 when you do 

M-: (scroll-left)
M-: (car (nth 6 (posn-at-point))) <ret>

The following error occurs

Debugger entered--Lisp error: (wrong-type-argument wholenump -62)
 posn-at-point()
 (nth 6 (posn-at-point))
 eval((nth 6 (posn-at-point)))
 eval-expression((nth 6 (posn-at-point)) nil)
 call-interactively(eval-expression)


In GNU Emacs 22.0.50.1 (i386-msvc-nt5.1.2600)
of 2005-10-04 on LD1
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-msvc (12.00)'

Important settings:
 value of $LC_ALL: nil
 value of $LC_COLLATE: nil
 value of $LC_CTYPE: nil
 value of $LC_MESSAGES: nil
 value of $LC_MONETARY: nil
 value of $LC_NUMERIC: nil
 value of $LC_TIME: nil
 value of $LANG: ENU
 locale-coding-system: cp1252
 default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
 flyspell-mode: t
 cua-mode: t
 recentf-mode: t
 show-paren-mode: t
 eldoc-mode: t
 which-function-mode: t
 tool-bar-mode: t
 encoded-kbd-mode: t
 mouse-wheel-mode: t
 tooltip-mode: t
 auto-compression-mode: t
 menu-bar-mode: t
 global-font-lock-mode: t
 font-lock-mode: t
 blink-cursor-mode: t
 unify-8859-on-encoding-mode: t
 utf-translate-cjk-mode: t
 line-number-mode: t
 transient-mark-mode: t

Recent input:
o l u m n <return> q <right> <right> <right> <right> 
<right> M-: <up> <up> <return> q <home> <up> <down> 
<C-next> n <C-prior> <left> M-: <up> <return> <C-next> 
SPC M-: <up> <return> <C-prior> <home> <right> <right> 
<right> <right> <right> <right> <right> <right> <right> 
<right> M-: <up> <return> <C-next> SPC M-: <up> <return> 
<C-prior> M-: <up> C-M-@ C-c <timeout> <return> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> <up> M-: <up> <return> <C-next> 
SPC M-: <up> <return> <C-prior> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<menu-bar> <help-menu> <report-emacs-bug>

Recent messages:
48 (060, 0x30)
Type y, n, ! or SPC (the space bar): 
38 (046, 0x26)
10 (012, 0xa)
Type y, n, ! or SPC (the space bar): 
0 (00, 0x0)
10 (012, 0xa) [2 times]
Type y, n, ! or SPC (the space bar): 
0 (00, 0x0)
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