simple FYI in the hope you can take a look at this.
- I ran through this twice to see if it would happen again and I did experience the same issue

Bug: could not re-oder the menu items

what I did to experience this problem:
I had some trouble getting the submenus to work and as such was moing some menu items from sub to top. When attempted to moe up these items (menu item ordering) mobile joomla with the iphone menu module from mobile joomla (that pointed to my mobile menu) did not get updated with the new menu item order.

I proceded by recreating a new mobie menu and linking this in the Joomla mobile menu iphone module.

- Menu item ordering should I assume work as it does on regular Joomla

My test enironment.
tested on iPhone 4 (no simultion - safari)
Joomal 1.5.23
php 5.3.6
mysql 5.1.56
host - Rochen
Mobile Joomla 0.9.12

Did you clear joomla's cache (actually, Joomla shoud do it itself, but to be sure...)?
Do you get the same issue after replacing mod_mj_iphone_menu by standard mod_mainmenu?