[plt-scheme] changing URL case in uri.ss (net)

After I started using 299.106, I noticed the the url.ss module in  
"net" changes the case of strings converted to urls:

 > (define foo "http://www.windley.com/foo?KeywordSearch=ten")

 > foo
"http://www.windley.com/foo?KeywordSearch=ten"

 > (url->string (string->url foo))
"http://www.windley.com/foo?keywordsearch=ten"

This is happening in string->url since urls constructed with it and  
sent to a server using call/input-url see the same thing.

This doesn't seem right.  Many parts of a query string are case  
sensitive and shouldn't be changed.

--phil--