kiwidude, Toxaris, & theducks: I owe you an apology.
You're completely right -- I had the ePub doc open in ADE when I tried to save it ... I hadn't encountered the problem before, because in the past I used the Firefox add-on to read ePubs while I was using Sigil, and that's stateless, so Sigil didn't give me an error.
I guess it would be wretchedly ungrateful of me to ask the Sigil developers --I mean, these guys are *volunteers* for God's sake -- to give me a more helpful error message, like "xxx.epub is open in another program" or something like that.
Regarding, the "IGotHired" style, I guess the people who wrote the original Word doc could have put such a style in, and I guess it could have carried over somehow to the XHTML file ... frankly, that feels like so long ago that it seems like ancient history. Once I put in my own "IGotHired" CSS style, I totally forgot about the issue, so I have no additional helpful information about it. I'd like to think that I could have been drunk, but the wine bottle is still unopened. Anyway, I've been working with 0.6 since then, and I've experienced no additional problems. I think it's a great program.
Sorry and Thanks, -Jeff