Problems with Session Strings Pro and keyswitches

I guess the only thing I've used keyswitches for extensively has been Trillian and it's always worked out fine. But tonight I've been trying to get to grips with the articulations in Native Instruments' Session Strings Pro (a Kontakt library) and I'm finding it problematic to say the least. 
 
What I'm finding is that even though SSP is receiving the keyswitches exactly where I put them (I can see this from the keyswitch screen), sometimes they just won't sound if I start the transport exactly at the switch. In fact the articulation is stuck on whatever it was on when I last stopped the transport . Sometimes I can get it to work properly if I press play and stop it a few times in succession. Other times I've gotten it to work by moving the switch note to another pitch and then back again (I know, weird). It's a real pain because it means I can't just play sections of the string part at will - the only way I can guarantee that all of the switches will work is by playing the whole thing from the start. 
 
And I'd like to emphasize that I'm not starting playback in the middle of a switch note - it's only ever right on the switch. 
 
I'm not sure if this is a problem with Sonar or with SSP and I wondered if anyone else uses it and whether they've had these types of problems with this or another instrument. 

Hmmm... I've never experienced this, but I always put the keyswitch before the first note with that uses the articulation I want so the keyswitch is finished when the new part plays. Session Strings behaves a little weird when changing articulations while notes are still sounding. If you move the keyswitch a few ticks and start playback slightly sooner - or a bar - can you get it to work properly then?

Hmmm... I've never experienced this, but I always put the keyswitch before the first note with that uses the articulation I want so the keyswitch is finished when the new part plays. Session Strings behaves a little weird when changing articulations while notes are still sounding. If you move the keyswitch a few ticks and start playback slightly sooner - or a bar - can you get it to work properly then?

Hmmm... I've never experienced this, but I always put the keyswitch before the first note with that uses the articulation I want so the keyswitch is finished when the new part plays. Session Strings behaves a little weird when changing articulations while notes are still sounding. If you move the keyswitch a few ticks and start playback slightly sooner - or a bar - can you get it to work properly then?

ProjectM
Is it clear now??  

:-). That's the funniest reaction to the multiple posts bug that I've seen.

Thank you for making me chuckle.