There appears to be a problem with std.uri.encode.

import std.uri;

void main()
{
    encode("http://www.digitalmars.com/~fred/fred's RX.html#foo");
}

>dmd.exe test.d
c:\dmd\bin\..\..\dm\bin\link.exe test,,,user32+kernel32/noi;
>test.exe
Error: Access Violation

XP/SP2 DMD/0.100