Maybe it's a pattern... Could you try the suggestions in this thread from yesterday: Custom added toolbars dissapear after a restarting firefox. Is anything there useful?

thank you for the reply,,,, I ended up resetting firefox then added the add-ons. didn't take that long. The problem is corrected!

Like I said in my last post I ended up resetting firefox then added the customized tool-bar with most of my add-ons. That worked fine until I decided to add the rest of my handy little add-ons. When I started firefox the next day my toolbar was gone

Not knowing at the time what the problem was I started over again and added another new tool bar with my add-ons hoping like an idiot it will work this time. When I went to add the Dr. Web link-checker add-on I noticed a reviewer mentioned he had lost his toolbar when adding the Dr. Web link-checker add-on. I decided to test it and added the Dr. Web link-checker add-on. After doing that I restarted firefox. Low and behold my toolbar was missing again.

So for me it was adding the Dr. Web link-checker add-on that caused my customized toolbar to go missing.