Strange wyswyg Problem

[maryx]

On my forum, if members use the word

forgot

in their post, the word does not appear! They can write

f0rgot

using the zero. They can write forget with no problem.

AND, this just started happening -- if they write

PR

as in the abbreviation for Puerto Rico, the words Page Ranking appears instead of PR. If they write it with a space between the letters

P R

it appears just fine.

Any help out there??