Mercurial Pull Crashes Apache Server

[Robert Schuon]

We run Mercurial on an Apache virtual server, and pull to an Ubuntu 
boxes normally, and with no, or only minor issues.  But I decided I'd 
like the repo at home, so I downloaded Mercurial 1.7 for Windows (I run 
Win XP at home), and the Tortoise 1.15 extension.   Everything installed 
smoothly, and I created a base repo to clone to.  However, every time I 
try to clone to the repo, or pull, or synchronize in any way, after a 
period of time our server locks up, and we get a 502 error.
Then of course, the Mercurial transaction fails, and it rolls back to 
zero.  First my question, and then a minor comment.  Has anyone had an 
issue like this, and what did you do to solve it?  The Mercurial part of 
the error is "Connection Terminated Abruptly", or words to that effect, 
because the server goes down.  I have tried creating a new repo, copying 
the repo as a zip, and just updating, nothing works.
My comment is, why does it roll all the way back to zero?  Why can't 
each changset be a transaction, so that if the transfer does fail, 
first, you get part of the repo, and second, have a clue where the issue 
is?  I have read the manual, I have personal experience with Tortoise 
SVN, so I think I know what I'm doing.  The worst part is not that the 
transaction fails, it's that it takes the server down, and it stops 
serving pages.  This is a mission critical application, and we can't 
have downtime.
Any help with this would be hugely appreciated.

Thanks,

Bob S.