MIDI sync problem

[keyoz]

Hey there,
I use Reason5.0 on Windows10 with ASIO4ALL and have connected my RC300 loop station via M-audio midiman to my computer's usb port. Since I cannot control the looper as a slave, I've set Reason to MIDI clock i.o. to control Reason externally. Although Start/Stop works perfectly, I have an issue with the playback song from Reason. It appears the song starts delayed, no matter if I increase buffer size. However, Arpeggiator values seem to be synced correctly to the RC300's MIDI clock signal. Does anyone have an idea?
Thx fwd

[keyoz]

Update: The RC300 starts and stops the song, though no matter what millisecond values I set in Preferences->Audio->Recording Latency Compensation, Reason will always either run away or delay on loop aging after 2 minutes or so. I get mad over this.... :/