Then it's a modified system core that's causing the issue. Since neither ILEX R.A.T. nor Semi-restore touches the core files, using either of them will not revert the changes made to them. Your only bet now is to attempt to re-install Cydia via deb package and see if that solves the issue assuming the issue's with the default packages associated with Cydia. If that's not the case, then it's a core problem and the only way to get your device running at 100% is to restore it.
If you have iOS 5.1.1 blobs with valid APTickets, you can attempt to re-restore using RedSn0w for a fresh copy of 5.1.1 on your device if the above does not work.
If you have iOS 5.1.1 blobs with valid APTickets, you can attempt to re-restore using RedSn0w for a fresh copy of 5.1.1 on your device if the above does not work.
