[notice] child pid exit signal Segmentation fault (11)

I get this error when trying to edit any nice menus block.

Doesn't matter what theme, only occurs when editing nice_menus blocks.

Here is all the info that I can provide to help:

Visting this url only shows a white page:
admin/build/block/configure/nice_menus/1

If it is modified to:
admin/build/block/configure/nice_menus/

Then it shows the 'edit block' page correctly (but this is of no use since it is for menu '0')

Here is my available updates page (All are up to date):

Last checked: 8 min 30 sec ago (Check manually)
Drupal 5.20
Includes: Search, Upload, Filter, Watchdog, Menu, Node, Block, Help, Contact, Locale, Path, Color, User, System, Taxonomy, Aggregator

CAPTCHA 5.x-3.2 Includes: CAPTCHA

FCKeditor - WYSIWYG HTML editor 5.x-2.3 Includes: FCKeditor

GMap Module 5.x-1.0 Includes: GMap Macro Builder, GMap

Google Analytics 5.x-1.9 Includes: Google Analytics

Internationalization 5.x-2.5 Includes: i18n - menu, Translation, Internationalization, i18n - blocks

Nice Menus 5.x-1.4 Includes: Nice Menus

Node clone 5.x-2.6 Includes: Clone module

Nodewords 5.x-1.13 Includes: Meta tags

Notify 5.x-1.3 Includes: Notify

Pathauto 5.x-2.3 Includes: Pathauto

reCAPTCHA 5.x-2.6 Includes: reCAPTCHA

Token 5.x-1.13 Includes: Token

Update Status 5.x-2.3 Includes: Update status

Webform 5.x-2.9 Includes: Webform

XML sitemap 5.x-1.7 Includes: XML Sitemap, XML Sitemap: Node, XML Sitemap: Engines

Server info:

# Apache/2.2.13 (EL)
# MySQL client version: 5.0.86
# PHP Version 5.2.11

My guess is some sort of conflict with another module, but not sure how to debug.