I had an unexpected power down and since then I have not been able to get to my local development site which is on my machine.
HTTP 500 Internal Server Error comes up when I try to go to the site. Since the error occurred the machine has been restarted but this made no difference.
I have a second copy of SS installed which I used for doing the tutorials in and this still works fine. It does access a different a different database.

I was in the middle of working on the site when the power went down.

I have checked the Apache error log and the entry is listed below.

This is the extract from the error log when I try to access the site.

[Fri Mar 06 10:02:05 2009] [warn] pid file C:/wamp/bin/apache/apache2.2.8/logs/httpd.pid overwritten -- Unclean shutdown of previous Apache run?
[Fri Mar 06 10:02:05 2009] [notice] Apache/2.2.8 (Win32) PHP/5.2.6 configured -- resuming normal operations
[Fri Mar 06 10:02:05 2009] [notice] Server built: Jan 18 2008 00:37:19
[Fri Mar 06 10:02:05 2009] [notice] Parent: Created child process 5824
[Fri Mar 06 10:02:05 2009] [notice] Child 5824: Child process is running
[Fri Mar 06 10:02:05 2009] [notice] Child 5824: Acquired the start mutex.
[Fri Mar 06 10:02:05 2009] [notice] Child 5824: Starting 64 worker threads.
[Fri Mar 06 10:02:05 2009] [notice] Child 5824: Starting thread to listen on port 3000.

Can anyone suggest what I should try?

Have put the system into Dev mode and got the following error messages

FATAL ERROR: DATABASE ERROR: Couldn't run query: INSERT INTO `PageView` SET Created = NOW() | Duplicate entry '1232' for key 1
At line 431 in C:\wamp\www\silverstripe3\sapphire\core\model\Database.php

user_error(DATABASE ERROR: Couldn't run query: INSERT INTO `PageView` SET Created = NOW() | Duplicate entry '1232' for key 1,256)
line 431 of Database.php

Database->databaseError(Couldn't run query: INSERT INTO `PageView` SET Created = NOW() | Duplicate entry '1232' for key 1,256)
line 108 of MySQLDatabase.php

MySQLDatabase->query(INSERT INTO `PageView` SET Created = NOW(),256)
line 81 of DB.php

DB::query(INSERT INTO `PageView` SET Created = NOW())
line 557 of DataObject.php

DataObject->write(1)
line 66 of PageView.php

PageView->record()
line 185 of Statistics.php

Statistics::collect()
line 84 of ContentController.php

ContentController->init()
line 17 of Page.php

Page_Controller->init()
line 126 of Controller.php

Controller->run(Array)
line 22 of ModelAsController.php

ModelAsController->run(Array)
line 104 of Director.php

Director::direct(/home)
line 158 of main.php

Context

--------------------------------------------------------------------------------

Debug (Debug::showError() in line 180 of Debug.php)
msg =
Couldn't run query: INSERT INTO `PageView` SET Created = NOW() | Duplicate entry '1232' for key 1
errorLevel =
256

Thanks for that Sam. Running db/build?flush=1 repaired the table and and I am now able to access the site. I am a bit confused though. I did try db/build?flush=1 a number of times since this error occured and each time simply got the HTTP 500 error message. The only thing that I can see that is different this time round is that I am in Dev mode.
Would this make a difference?