I'm writing a c++ Ruby extension that seems to be running into some kind of a memory issue. I'm getting "HEAP: free heap block modified after it was freed" when I attempt to either allocate a new array(rb_ary_new) or push onto a ruby array(rb_ary_push) at a certain point in my program. I can't seem to find any buffer overflows - which I believe is one cause for such an error. So it leads me to believe that maybe my "marking" functionality may be flawed. But as far as I can see I'm handling the marking properly - I mark anything that is not a fixnum( arrays, other classes, etc). Are there any newbie marking mistakes anyone knows of that could cause an issue like this? This problem only happens when my extension uses a decent amount of memory - so I'm not sure if there is some kind of a Ruby heap limit that I'm going over. I'm just curious if anyone has encountered a problem similar to this that they have overcome? Its been almost a week where I have essentially been at a standstill with development. I've even got an evaluation of Insure++ to help me look for memory issues - all to no avail. Thanks, Let me know if there is any additional information I can provide to clarify any details. Joe