toString not working... (a bug in D?)

[Orgoton]

Ok, now I did

import std.string;
ushort number=1092;
char[] text="Some text " ~ toString(number);

and the compiler claimed that the number of arguments of Object.object.toString()
did not match... So, I did

char[] text="Some text " ~ std.string.toString(number);

and it worked fine. Is this a compiler bug? I did not import object (as it is
implicitly done). Or have I some weird compiler configuration?