lucy24 - 9:08 am on Feb 13, 2012 (gmt 0)
and then is presented with code 500 errors
Whaa? Getting an URL wrong shouldn't result in 500 errors. 404* at the most ;) A 500 error means your server is seriously upset about something. You should look into it a little more closely.
* This reminds me that GWT "Crawl Errors" is showing pages as 404 "not found" when they are clearly and unambiguously 410 "gone". (Set in htaccess and confirmed by logs.) I do not care for this at all.