Wikipedia underscore issue

[GoogleCodeExporter]

I use the following regular expression for Wikipedia which works well for me:

^http[s]?://([^.]+\.)?(wikipedia\.org/wiki)/(Special:Search\?search=)?([^&]+)

However Wikipedia replaces blank spaces with underscores (_) which appear in 
the search box.

What steps will reproduce the problem?
1. Add the above regex as a new Wikipedia entry in SearchBoxSync settings;
2. Search for `Tom and Jerry` (or any other query containing a blank space).

What is the expected output?
The query in the search box remains unchanged.

What do you see instead?
The query in the search box changes to `Tom_and_jerry`.

What version of the product are you using? On what operating system?
Windows 7 Home Professional 64-bit
Windows XP SP3
Firefox 8.0
SearchBox sync 1.4.0

Please provide any additional information below.
This happens only when queries contain intervals/blank spaces.

Original issue reported on code.google.com by [email protected] on 18 Nov 2011 at 10:15