Příčina se jmenuje AVI 1.0. Stáhni nejnovější verzi.
http://www.fraps.com/news.php
Fraps 3.5 adds the much requested feature to allow AVI movie files larger than 4 gigabytes. Fraps will now write hybrid OpenDML/AVI files and allow large movies on NTFS drives. There's still an option to split at 4 gigabytes for legacy AVI 1.0 support.