I just really nowticed that I should have posted my message in this forum instead of the original one. So, in an effort to not duplicate the post I just use this as a pointer to the right post. I hope that the correct eyes see this one. The short and skinny is that root crashes when I try to read a root file from an old version of root. Specifically the file is readable in root ver 3.05 but crashes 4.04. It crashes as soon as I try to read an event. Follow the link to the full post. If there is any other information that might be relevant please do not hesitate to ask. Thanks in advance.