Weird Eudora font issue

[dsnyder]

One of my clients recently bought a Powerbook G4 to replace his aging PB G3.

I installed Eudora 5.1 for him, and transferred his settings and mail from the G3 (which had Eudora 5.0).

If he has the screen font set to particular fonts (one of them being Arial-- I can't remember the rest, but Arial is the one he would like to use), parts of letters do not show up while his is typing.

For instance, only the left half of the "r" should up, and apostrophes don't sometimes don't show up at all. If he hits return to go to a new line, the characters magically return to normal. Also, changing the screen resolution fixes the problem for character that have already been typed, but it goes right back to screwing up when he starts typing again in the new resolution.

The same fonts work in Office 98, SimpleText, Keycaps, IE, and Netscape.

I have exactly the same OS (9.2.2) and Eudora version on my iBook, and I don't have this problem at all. I tried replacing his Arial font with the copy from my machine, but it didn't make a difference.

Any ideas?