SEO Settings -
SEF URLs - YES
Use URL Rewriting - NO
Adds Suffix to URL - NO
Unicode Aliases - NO
Include Site Name in Page Titles - NO
Cookie Settings - all blank
Turning off SEF changes the link obviously, and the pipe '|' character shows between the categories: ...catids=8|12|24|13&filter_reset=1...
However, it still gives a 403 - Forbidden Error.
I tried different combos of YES/NO with no fix to the 403.