Trying to upgrade to version 7 but the pdf file created from the php script is empty. The error log shows this at the end:

Sat Dec 12 14:37:47 2009: Converting document...
Sat Dec 12 14:37:47 2009: internal error: domain_error("float:\'/\'")

Anyone with ideas? I run Ubuntu 8.04 and installed the correct version.

Very interesting. Would you be able to email me (mikeday@yeslogic.com) a sample input document that demonstrates this behaviour?

Solved! Thanks for the help Mike. For any readers the css of my TOC was flawed.

#navig a::after { content: leader("") target-counter(attr(href), page);
changed to

#navig a::after { content: leader(" ") target-counter(attr(href), page);

It's been a while, but this empty leader issue has been fixed in Prince 8.0. Thanks for letting us know.