It told me to file a bug report so I am. 
the problem started because darcs failed to recognize changes in 2 files. So I copied those files to a different via ssh and then on that remote box recorded the changes. Then, back on the initial box, I tried to pull the changes (which would have resulted in files that were identical to what was in my dir ... obviously). Here's what happened when I did my pull.

You will find the pending_buggy file attached and below you will find the output from the session that barfed. The exact-version of the local machine and the exact-version of the machine I pulled from. 

I would also note that the code recommending I file a bug points to the wrong location for the pending_buggy file. It states _darcs/pending_buggy but it was actually in _darcs/patches/pending_buggy

----- 
the run that barfed

krhodes@3LK2XC1:~/workspace/breakdown2$ darcs pull masukomi@masukomi.dyndns.org:/projects/breakdown2

Pulling from "masukomi@masukomi.dyndns.org:/projects/breakdown2"...

Thu Jul 12 17:38:23 EDT 2007  masukomi@masukomi.org
  * ADDED REAL LINES COUNT TO REPORT
Shall I pull this patch? (1/1) [ynWvxqadjk], or ? for help: a
We have conflicts in the following files:
./bd2.py ./templates/index.tpl

Fail: bug in darcs!
There was an attempt to write an invalid pending!
If possible, please send the contents of _darcs/pending_buggy along
with a bug report.
Please report this to bugs@darcs.net
If possible include the output of 'darcs --exact-version'.
--------
The output from --exact-version on my local machine (which told me to file a bug)

darcs compiled on Feb 12 2005, at 13:59:36
# configured Sat Feb 12 13:53:58 PST 2005
sh ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib --mandir=/usr/share/man

Context:

[ removed obsolete NEWS files
Isaac Jones <ijones@syntaxpolice.org>**20050212211000]

[syncinc with my debian repo after 1.0.0 bug
Isaac Jones <ijones@syntaxpolice.org>**20050212205746]

[TAG 1.0.2
David Roundy <droundy@abridgegame.org>**20050204123805]

---------
The output from --exact-version on the remote machine that i recorded on and was pulling from:
darcs compiled on Feb 12 2005, at 13:59:36
# configured Sat Feb 12 13:53:58 PST 2005
sh ./configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib --mandir=/usr/share/man

Context:

[ removed obsolete NEWS files
Isaac Jones <ijones@syntaxpolice.org>**20050212211000]

[syncinc with my debian repo after 1.0.0 bug
Isaac Jones <ijones@syntaxpolice.org>**20050212205746]

[TAG 1.0.2
David Roundy <droundy@abridgegame.org>**20050204123805]

krhodes@3LK2XC1:~/workspace/breakdown2$ ssh masukomi@masukomi.dyndns.org
Password:
Response:
Last login: Thu Jul 12 17:37:28 2007 from fw01.cmbrmaks.a
Welcome to Darwin!
Moonolith-3:~ masukomi$ darcs --exact-version
darcs compiled on May 30 2006, at 09:25:54
# configured Sat May 13 19:49:56 EDT 2006
./configure --no-create --no-recursion

Context:

[TAG 1.0.7
Tommy Pettersson <ptp@lysator.liu.se>**20060513171438]

Attachments

• pending_buggy

Thanks for the report!  I believe this bug has been fixed a while back.  Could
you upgrade your darcs to the latest released version (1.0.9) and let us know if
it's fixed?  Marking resolved for now.