Errors in error_log

[enci]

Thanks!

--------------- Added [DATE]1206032513[/DATE] at [TIME]1206032513[/TIME] ---------------

Here are some lines taken out of my access_log (with domains, etc. changed) that I do not understand, nor am I able to recreate the errors.

FYI:
* Forum is located under website.com/forum
* Name of forum is "forum-name"
* Website domain is website.com
* We are currently using vRewrite

The first two lines of the log are fine. The third line forward, however, are 404 errors.

Line 1: 196.217.249.190 - - [20/Mar/2008:03:00:21 -0800] "GET /forum/showthread.php?t=67769&goto=lastpost HTTP/1.1" 301 - "http://website.com/forum/showthread.php?t=67769&goto=lastpost" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 2: 196.217.249.190 - - [20/Mar/2008:03:00:52 -0800] "GET /forum/forum-name/t-name-of-post-1234.html HTTP/1.1" 200 40739 "http://website.com/forum/forum-name/t-name-of-post-1234.html#post473115" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 3: 196.217.249.190 - - [20/Mar/2008:03:00:58 -0800] "GET /forum/forum-name/register.php HTTP/1.1" 404 10647 "http://website.com/register.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 4: 196.217.249.190 - - [20/Mar/2008:03:00:59 -0800] "GET //website.com/forum/forum-name/register.php HTTP/1.1" 404 10647 "http://website.com//website.com/forum/forum-name/register.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 5: 196.217.249.190 - - [20/Mar/2008:03:01:00 -0800] "GET //website.com//website.com/forum/forum-name/register.php HTTP/1.1" 404 10647 "http://website.com//website.com//website.com/forum/forum-name/register.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 6: 196.217.249.190 - - [20/Mar/2008:03:01:01 -0800] "GET /forum/forum-name/register.php? HTTP/1.1" 404 10647 "http://website.com/register.php?" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 7: 196.217.249.190 - - [20/Mar/2008:03:01:02 -0800] "GET //website.com/forum/forum-name/register.php? HTTP/1.1" 404 10647 "http://website.com//website.com/forum/forum-name/register.php?" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
Line 8: 196.217.249.190 - - [20/Mar/2008:03:01:03 -0800] "GET //website.com//website.com/forum/forum-name/register.php? HTTP/1.1" 404 10647 "http://website.com//website.com//website.com/forum/forum-name/register.php?" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"

First, in line #3, why is the person coming from website.com/register.php? The file is located in website.com/forum/register.php.

Line 4 and 5 are just weird because it looks like they're being redirected somewhere. Has anyone seen this issue in vrewrite? Again, I cannot replicate this error, so I don't know where it's happening. It seems to happen to some people and not others. I even tried to retrace the path of the IP address, but nothing.

Line 6 is odd because the referer page does not exist (again, it's not in the /forum subfolder), but the page it's trying to access should exist because it is in the subfolder /forum. But where does the variable "s" come from and is that why it's causing the error?

The rest of the lines are along the same lines.

I have been trying to figure this out for a long time but all I can chalk it up to is an issue with vrewrite, but I'm not sure. It seems like I've seen an increase in these errors the last few weeks and I wonder if it's affecting my rankings.

A big thanks to anyone who can help bring a little bit of clarity to this issue for me.