I have the same issue, and have not been able to solve it.
My phone was connecting to both PCs fine (windows 7, 64bit)
you plug it in, it shows up as a PTP, or an MTP. (i would RATHER it show as a drive, like the old Droid X, which i do not understand why this is not an option to mount the VZW versions of Galaxy as a drive...but anyhow)
I updated to 4.1.1, and it was still the same...HOWEVER, the battery was being drained constantly. I could not get a day's use out of it.
So after all of the searching and speaking with reps, it was determined a clean install/factory reset was needed.
So i did.
1. this did NOT solve the battery issue. my phone is less than a year old, and the battery under Jelly Bean 4.1.1 is being drained in well under a day with very normal to little usage. i will unplug it from a full night of charging and it immediately sinks to 98% and keeps draining.
2. now when i connect it to the PC, on one PC it will show the "Connected as Installer" issue, and mount as a CDrom. I am unable to delete these files (why?) and they go away too quickly to determine where they are located...THEN it shows up as a PTP or MTP.
3. on the other computer, it will not show at all. it only charges. USB ports are working fine on the computer, and know my phone DID show fine until i did a factory reset.
what am I missing here Verizon?