multithresh randomly(?) outputs this error...

"Attempted to access omega(-1); index must be positive integer or logical"

I don't know if this is a bug or it has been answered before but...

I run threshold = multithresh(I,n), and occasionally get the error above. I repeat the line (no changes) and then it continues to work. The image I is just a 2000x2000 image of type 'single', and n is a scalar (often 5 or 6). My questions are:

a) Why am I getting this error at all, and b) why am I getting it at random times? c) I haven't inspected the code but could this be a bug?

Thanks in advance.

[Ashish Uthama]

Sounds like a bug to me. Are you repeating the exact same inputs? If you get any kind of reproduction steps, I would encourage you to contact tech support: http://www.mathworks.com/support/contact_us/