Repeated crashes of Thunderbird and Firefox

[Fulvio]

Today, Thunderbird 3.1.9 and Firefox 3.6.16 crashed at least three times. This morning Thunderbird opened with no list of accounts, first. After closing, it opened, and downloaded, very slowly a total of about ten e-mail, taking about fifteen minutes. Only one e-mail had an attachment of about 1 MB. I opened one e-mail, and the second one made the program disappear after I clicked on a link which opened Firefox. Firefox disappeared, also.
This afternoon the same thing happened. At the third attempt, the reporter came up for TB, but never for Firefox.
Neither Firefox nor Thunderbird ever crashed on me before.
I had a unresponsive script message of iterator.utils.jsm, this morning. A similar problem was reported at getsatisfaction. com,but there was no useful reply.
It seems that if I stick to this site I am ok, but almost anything else seems to be a problem. And, why no reporter coming up, except in one case?

UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.16) Gecko/20110319 Firefox/3.6.16

[Fulvio]

So far so good.
I must add that, somehow, I picked up a virus/worm, called hpospd08.exe. When and how, I have no idea, but Avast made a ruckus when I did a full scan. It removed that file, as well as the same in System Restore.

UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.16) Gecko/20110319 Firefox/3.6.16