Rusty,
Speed Encoder is as stable as something can be. Since the software uses 100% CPU power there may be something wrong with your computer. Rebooting may be an indication that it gets too hot or the PSU can't provide enough juice under full load. It's not always the software.
In my opinion Speed Encoder is a Junk App. I gave 3 attempts to render a one-hr. segment... each ending in a violent windows crash and automatic machine restart.
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