I've been using reason for about three years now. I've been using an Akai MPK49 for almost a year, and I've recently been having pitch problems with Reason 4. I'll be playing on the keyboard, and randomly Reason will automatically transpose, often when I'm holding down multiple notes or using the pitchbend/mod wheels. Sometimes it's a half step, sometimes it's more. It also only affects the patch that I'm playing on. This has been a big problem, as I use Reason in live performances. Has anyone experienced this or heard of similar issues?

I'm using a 2006 Macbook Pro. 2 Gigs of RAM. 2 GHz

Found this on another board:
"Hi guys, i observed the same problems with reason and the mpk, but i think i have solved it now:
First: Be sure that you use the latest codecs and remote maps for mpk. You will find them downloadable from the akai professional website (.com! the german site has old versions...). Install them as described and remove older versions of the files (to be save)
Latest firmware of the MPK is also required, certainly, 1.03 I believe, but that was already installed when my mpk arrived.
Then set reason to receive incoming midi clock signals from the usb input port of the mpk (under options/advanced midi controls). Then set Reason to be synced as slave
The akai must be set to internal midi clock. And the play/stop etc buttons
must be assigned to send Midi/MMC data! Not midi alone!
As result arp and note repeat works fine!! And probably due to new remote codes my pitch bend error that was described above was gone, also!... "

__________________
Refills Here: http://www.3rdfloorsound.com