Using lynx to change the number of displayed entries gives "Bad request error". I think the extra space character is the culprit. http://www.wikipedia.com/w/wiki.phtml?search=History
&limit=50&offset=0
I can't see how you managed to enter that extra space. Spaces are illegal in URLs, and I couldn't find any way to get Lynx to let me enter one. The links on the page are correct, the code does exactly the right thing, and even when I typed in the URL manually Lynx removed the space for me.
In any case there's nothing I can do--you are in fact making an illegal request, and software is correctly reporting that fact. If the software were itself /generating/ a bad link or someting, then that would be a bug.
I looked up "History" and it was rather strange that "History of Asia" was not listed in article titles section but only in article text section.
It shows as listed for me--it's #73.