First, it sounds like you are actually using Adobe Illustrator in the example of not being able to Export to PDF. In Illy it is done using a Save As function. In ID, one uses Export.
As for the fonts, all Adobe fonts that ship with their products will output to PDF. Some 3rd party fonts are restricted. What font(s) does the message refer to--what font(s) are you using?
And is it really failing, or just popping up a warning about licensing requirements for font embedding? A warning dialog would be normal.
adobe reader gives me thi message: "The font 'Krungthep' contains an invalid encoding. Some characters may not display."
why would some characters not display?
illustrator gives me this message: "The font Krungthep could not be embedded in the PDF document because of licensing restrictions. Stroked text will not be visible."
so is this normal? If it is can i use it publically then for logo & such?
Yes thank you that clears up the exporting. I was using the font krungthep.
I haven't been able to learn much about Krungthep, other than it appears to be used for Thai. A lot of the older Thai fonts are not unicode encoded and can display oddly under some circumstances. If joould is watching, he can provide more information.
In any case, the font cannot be embedded according to the warning you are receiving. That means anyone opeing the PDF who does not have Krungthep installed on their computer will have a problem reading your text. The best advice is to find another font.