MIDI playback slows down - RESOLVED

Hi,
I'm about to pull my hair out.  I sent a song to a drummer friend of mine with a click track included.  He played along and sent me the midi file, which I imported into Sonar. 
 
Unfortunately he didn't set the tempo in his DAW properly, so I had to 'lengthen' the MIDI file and synch up the start points, but that seems to have gone well - the first 60 seconds of the midi file played through a BFD2 or Session Drummer 3 plugin are perfectly in synch - however at about 1 minute, the  midi goes out of time using either plugin and gets worse as the tune continues.
 
I've ensured:
- buffers are set properly in Sonar & RME configuration utility (e.g. they match)
- I've appended the 'ignoremidiintimestamps' in my ttsseq.ini
- Playback and timing master in Sonar is set to my RME analog output channel 1
- There are no tempo changes in the tune or in the midi information (in tempo view)
- I've tried playback at all buffer settings
- I've bypassed all FX (except for BFD2 or Session Drummer 3)
all to no avail.
 
My setup is:
Sonar X1a PE 64 bit on Win7 64 bit w/ an RME Fireface UFX running via Firewire on a Dual Quadcore Xeon 3.2 Ghz CPU w/ 8 Gbyte RAM and 3 separate disks (1 for OS & apps 1 for BFD2 samples & 1 for Sonar data) and Nvidia Quadro FX1700.  RME and Nvidia have latest drivers.
 
Any other ideas?
Thanks!
Russ
 

Karma,

Simply starting at the same point will not lock the tracks up for the duration of the song. It's close - very close if you can get a minute out of it, but it's only natural that it won't last the entire song.

There might be other ways, but I think you need to create a tempo map to follow the midi track. A very slight adjustment here and there to keep things locked up.  Take a look at this video for an idea. It's an older version of Sonar, but the same principles should apply.

http://www.youtube.com/user/dustypuppy?blend=2&ob=1#p/u/62/cP_4X5QdppE

Codamedia,
 
Sorry, I just re-read your note and want to ensure I'm clear. 
 
You're saying the 'lengthen' MIDI Process wouldn't synch through the entire song?  Assuming you lengthened by the proper %, I thought that's exactly what it's supposed to do by modifying the start time and duration of the midi notes to the new tempo?  The only other thing required is then to synch up the beginning so the newly modified midi track starts at the right time.
 
Am I confusing something?
 
Thanks for your help.
Russ
 

DOUBLE POST