Batch command line "convert" tool corrupting first file in folder

-convert txt * -output *

I am batch converting some RTFs to TXTs. For some reason, the first (only the first and always the first) file in the directory does not convert AND gets corrupted by the conversion.

As a hack, I create another fake file and make sure it is the first file in the directory. I get my successful conversions; I then discard the fake file.

Is the command listed above the best way to say, "convert all files in this directory to text files"? What might be causing the first file to become corrupted?

I don't know if this might have anything to do with it, but the containing folder is on the desktop.

Any help is appreciated.