Deploy Lion app to 10.6 exception

Question

I have an OS X App That builds on Lion (with latest sdk) but deploy set to 10.6 (to be able run on Snow Leo). ARC enabled.

I want's to run app on Show Leopard. Application works well on Lion.

But when I start application in 10.6 I get this exception in console:

NSRLEArray objectAtIndex:effectiveRange: Out of bounds

And nothing more. No stack or whatever. Just this one line.

What I may do to clarify situation ? Problem seems more strange, since in Lion all works good.