[imp] IMP 3.1/Horde 2.1 "No Data" Error

[mjp at jesuits.net]

Hello,

I have been using Horde 2 and IMP 3 for some time.  Some of my users
experience a strange problem in which they get "Document contains no
data" errors intermittently when they log into their accounts.  I've
isolated the problem and determined that it only happens when the to
or from addresses in the headers of messages in their inbox contain
accented characters.  These accented characters, of course, are in the
"real name" part of the address, but they still cause the no data
errors.  The php log shows a seg fault for the php process when this
happens.

I am using IMP 3.1, Horde 2.1, PHP 4.3.0, and Apache 1.3.27.  I did a
maddening round of upgrading, hoping to solve this problem, but it
didn't help.  My users are a bit tired of the whole thing, and I'm
very tired of manually deleting accented characters from their email
headers.

Does anyone have any suggestions for this?  

Thanks very much,
Matt