Long story short... I found my old flash drive in which I had a whole bunch of modded patch.ff, FileManager, and Back up from the firmware that was out (3.55). When I saw a back up folder I already knew it was from the time 3.55 cfw was out.
So I restored my ps3 with the back up that I checked the system firmware and it was on 3.72. (I was currently on 3.73) I was hoping that it was going to go to 3.55 but it only went to 3.72.
So basically I'm trying to say that if you have a back up on your flashdrive with important jailbroken programs try to restore your ps3 and see what you get. YOU NEVER KNOW!
Err - backup (of user data) has nothing to do with firmware - they're each kept in totally separate areas and FW partially (on older PS3 models even completely) in the NAND / NOR chips so there is no way of "downgrading" by restoring the backup. The only explanation for what you've experienced would be the non-mandatory upgraded released apart of the full upadate also in the form of patch only (as indeed was 3.72 -> 3.73 and a couple of similar before) and fact that the patch replaced just some minor files on the hard drive rather than the whole FW. Then - I'd believe that it COULD have gone "back" to 3.72 FW but even that it's would not lead to anything major so don't get your hopes high ...