Lisa,
On eham.net, you'll find that the first reviewer for the Grundig Mini
300 noted that his unit was "usually reading 5khz high across all of
the bands."
see:
http://www.eham.net/reviews/detail/4761
So, if the displayed frequency occasionally reads off by 5 kHz, it
could well be that your 15545 @ 20:15 sportscast was actually the 15540
kHz RPI program and your 7115 @ 03:22 actually R. Republica on 7110
kHz.
If this is the case, then you'll find that your new Kaito '1101, being
a PLL synthesized unit, will receive these transmissions 5 kHz lower
than what your Mini 300 was displaying.
Best of listening to you.
junius