You already verified that it is not installed to your SD Card, correct? I can't remember if we already tried that.
No, it is not installed on my SD card.
It sounds like you might need to do a wipe/reinstall then.
Girluvsdroid did a great walkthrough that I use to simplify the process. I copied it here for you:
1. Go into your launcher settings and backup both the settings and desktop configuration (depending on which launcher you are using).
2. Get Titanium Backup if you don't already have it and go to Batch and use "Backup all user apps + system data."
3. Make sure you don't have any backup directories from other ROM app backups on your SD card (this does not include nandroid backups or those from Titanium Backup, My Backup Pro, and similar applications -- but some have reported that Astro backups cause issues, so you may need to delete those).
4. Do a nandroid backup of your current setup, then, using ClockworkMod Recovery, do a factory reset (wipe data and cache), then go into the partitions menu and do a wipe of boot, then of system.
5. Install the ROM zip file and wait until it reboots again after the first bootup (this could take a while -- be patient).
6. Sign in to Google and immediately open the Market, search for Titanium Backup (I call it TiBu) and restore it.
7. Make sure you have "Unknown sources" checked in System>Applications.
8. Open TiBu and go into Preferences and make sure you have "Force to same location" checked (this will then make sure your apps and data are restored to the device and SD card, as applicable, exactly as they were when you did your backup).
9. Go into Batch and and start with "Restore missing apps + all system data" -- but
here's the important thing: press "Deselect all" and ONLY check the items in
GREEN (this will restore all your call log, SMS/MMS, wifi and bluetooth connections, etc.). If you restore the stuff in red, you're restoring system data from prior ROMs, which could cause you all kinds of issues. We'll do apps and data in the next step.
10. After you've finished restoring the items in green, run "Restore missing apps with data" and go through the list and make sure you've got only the items you really want to restore checked.
11. After you've finished with that restore, reboot into recovery and wipe the cache partition, which in my experience helps jumpstart the market sync.
Now, there may be some apps that restored from the Market that don't have your data. If you run across one of those, just go into TiBu and go to filters, type the name of the app, and restore data only.
The only thing left is that you'll likely have to set up your widgets again (at least I do in Sweeter Home 2) or restore them using the backup you performed in step 1.
One other note: if you have Swype, I've found that TiBu restore doesn't work right. You'll want to reinstall the Swype installer, then Swype
FIRST, before your TiBu restore, to avoid the memory issues that plague Swype installs.
Hope that helps, and sorry I couldn't figure out an easier fix for you!