Errors in script and characters on websites
Sometimes on websites like blogs or especially on twitter many of the characters are no longer english language but some sort of script. Sometimes when I have to respond of fill in a text box my response types in these same symbols. How do I fix this?
Opaite Mbohovái (1)
This issue can be caused by an old bitmap version of the Helvetica or Geneva font or (bitmap) fonts that Firefox can't display in that size.
Firefox can't display some old bitmap fonts in a larger size and displays gibberish instead.
You can test that by zooming out (View > Zoom > Zoom Out, Ctrl -) to make the text smaller.
Uninstall (remove) all variants of that not working font to make Firefox use another font or see if you can find a True type version that doesn't show the problem.
There have also been fonts with a Chinese name reported that identify themselves as Helvetica, so check that as well.