[mod_python] Odd behaviour with handlers

I've found that if, for the same apache setup, there are two separate
sites defined with a handler of the same name (but not the SAME
handler) the server will jump unpredictably between them. So if
http://example.com/a uses a handler for webapp X, where the handler is
called mainhandler, and http://example.com/b uses a handler for webapp
Y, where handler is also called mainhandler, going to
http://example.com/a may get you either webapp X or Y, seemingly at
random. Is this expected behaviour? If so, might be worth warning
about it...
Rob