ajp13.service() Error sending initial post -1 32 0

Hi All,
Does anyone have any idea what the above error message means?!?

On our site, we have a large textarea which we post to another page.
Depending upon the size (AFAIK), we will either get the correct page (if its
small enough) or the above error in the Apache error logs (if its over a
certain size).

Looked on google, with no luck.

Any help is greatly appreciated.

Specs are:
Solaris 8 on Sparc
Apache 2.0.43 (from the pre-built binary)
Tomcat 4.1.27
Using mod_jk2 v2.02

TIA,
Pete