Thanks hackedintosh!! you solution work perfectly!
Once i was done replacing installr.app it told me there was an update, i applied it and it works just fine.
fro the noob out there here is a expanded version of ur instructions:
1 download
http://repository.apptapp.com/packages/System/Installer.zip 2 download Fugu (mac only - im not sure about a windows alternative)
3 ssh to your iphone - open terminal and enter 'ssh root@<iphone address>'
4 enter your root password
5 type 'cd /Applications'
6 type rm -rf Installer.app
7 open fuzu - enter the ipaddress of the phone in address and root as the user.
8 enter the password when asked
9 change the folder to application and drag installer.app into the iphone window. This will copy the file over
10 go back to terminal and type 'chmod +s Installer.app/Installer'
11 next type 'chown -R root:wheel Installer.app'
That should be installer running again!