Problem with bot-indexing of my .asp pages...

Hello,

I need advice of professional, who knows about indexing of ASP pages by MSNbot, Slurp etc.

My worry:
Today I replaced on FTP my html-site (static) to asp-site (dynamic). Soon I saw in logs strange behavoir of both bots.

MSNBot - 207.46.98.59 - - [09/Oct/2004:16:42:29 +0000] "GET /company_sell.asp?|3|800a01a8|Object_required:_'[undefined]' HTTP/1.0" 500 0 "-" "msnbot/0.3 ( http://search.msn.com/msnbot.htm)"
There is something about error 500 - but links and functionality of my new site has no problem, so what this error meens?...

Slurp bot:

1. 66.196.91.40 - - [09/Oct/2004:18:32:05 +0000] "GET /download/regform.txt HTTP/1.0" 200 26442 "-" "Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)"
File 'regform.txt' was removed about month ago, but Slurp reads it as 200.

2. 66.196.90.84 - - [09/Oct/2004:18:32:29 +0000] "GET /download/legend.asp HTTP/1.0" 200 26387 "-" "Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)"
Strangely to see data above, because in folder Download I never had such file (legend.asp). But when I enter such URL into address bar of browser, I see broken page 'legend.asp', when it doesn't exist at this folder at all....

Please, explain me, what's going on with my site?

Regards,
Spaniard