Error message when trying to reply to private messages

Lately I have been getting this message when I try to reply to PM's - not all the time, but several times it has happened:

Microsoft VBScript runtime error '800a000d'

Type mismatch: 'SendPrivateMessage'

/m/TestSpam.asp, line 170

It looks like it has only happened when using Firefox, but again it does not happen all the time, just sometimes.

I also have to make the size of my type "Medium" for it to appear the same size as "Small" in IE.

I would just log in only at IE, but I use Firefox to be logged in as Tony Isaacs and IE to be logged in as Dquixote1217, which is much easier than switching back and forth in IE - and switching also creates problems because I will be logged in as one ID and it will often revert to the other one - not cool when I venture into the minefield of the debate forums on occasion.  Besides being a forum owner, Tony Isaacs is a kinder, gentler soul while that DQ guy can get a bit rowdy at times.  Say, is there a forum for multiple personality disorder?

Tony