Zoho Spell Checker Issue

I have used your program for two documents. Each time I am only able to run the spell check one time; otherwise, I must close out and come back to run it again. It seems to hang up in some kind of "suspension." Also, several words were not caught, but Blogger caught them with their spell checker. I read about this site in a Web 2.0 book, but not convinced yet. The spelling thing is a big issue. I'll hang in there if anyone can explain this... Oh, I use Firefox, and I'm up to date on all my programs, including XP. Any ideas on this?
debrajwrite