Installer Errors!

I've been having issues with the installer on my jailbroken 1.1.3 ipod. Many apps I try to install will download, then when the status bar comes up for installing the screen just gies back to the springboard without installing it. It does this with most apps I try to install and it MAY have starts with the psx4all app. I tried installing that one and the icon is on my springboard, but in the installer it is NOT under the uninstall tab, and when I try to use it it crashes my ipod. It is still listed under the install tab in the installer but I am unable to install it just like many other things.

Please help me.
(I use a PC)