Problem: I want Computer Modern fonts in my presentation, but these weird text-land fonts show up in my equations. CM are there in dvi and ps (and even pdf) when I use gv for preview, but disappear in Ad0b3 Reader.
(Btw, I needed to use a symbol, and to use it I used the package txfonts (or pxfonts). That couldn’t hurt?)
Resolution: txfonts adjusts Times for mathematics, and pxfonts adjusts Palatino. Thus, these packages effect all the math, and are not “just for a few symbols” packages.
The symbol you’re looking for — if you found it in tx/pxfonts — will definitely be available from some other package (latex pre-defined or amsfonts, etc.); so look harder in symbols-letter.pdf (or symbols-a4.pdf) and DON’T use tx/pxfonts if Times/Palatino math is not your thing.