The problem is that the audio_fill_seq function try to load the hd file if the sequence don't have it, but it join the two string (directory path + file path) without the / (Linux... \ Windows), so the result is a wrong path. I change the the strncpy and strncat function for a BLI_join_dirfile (like the reload_sequence_new_file) and all work fine now. Also note that the "them go" that Luca report is (or what happen here) the ctrl+z function, and now both case work fine here. (interesting.. date from Feb 05.. 2006 ;)