[imp] attachment problem ("Read POST information timed out")

[liamr@umich.edu]

I'm having a problem using Safari to upload attachments w/ Horde 3.x / IMP 4.x
(release and HEAD) / PHP5.0.5.

The problems go away if I downgrade to PHP 4.3.x, or I don't configure IMP to
use VFS for attachments, but if I do use VFS (filesystem based, or sql based),
I frequently get...

    [Wed Nov 16 15:41:56 2005] [info] [client www.xxx.yyy.zzz]
        Read POST information timed out
    [Wed Nov 16 15:41:56 2005] [info] [client www.xxx.yyy.zzz]
        client stopped connection before rvputs completed

In my php.ini,

    file_uploads = On
    upload_tmp_dir = /var/tmp
    upload_max_filesize = 10M

and LimitRequestBody isn't set in our apache configuration, and the apache docs
say that the default for LimitRequestBody is "0" (unlimited).

Any ideas?

Liam