Really long solutions

I'm seeing really long "solutions" being reported in my log:
post blocked by CAPTCHA module: challenge Image (by module image_captcha), user answered "45jy", but the solution was "8e44af2ffdc7784948bdfcce79becd5a".
post blocked by CAPTCHA module: challenge Image (by module image_captcha), user answered "pae4", but the solution was "7be495145b19ca224e2ed91ed45763a1".

What could this be? I have it set to code length of 5.
My webform ave been getting whacked from Russia with multiple hits seconds apart, could this just be a malformed Log in some way?
Thanks,
Mark