Recently installed an 120GB SSD for the OS in the optical bay and replaced the original 250GB with a 750GB HDD for 'users'. OS was Snow Leopard. Ran for a couple of months, worked great. Decided to U/G to Mountain Lion. Download & install went fine but:
1) Can no longer mount my QNap NAS on my home network. Can see it the Finder sidebar, but won't connect, just says 'connecting'. Activity monitor is showing Netauthsysagent using close to 100% CPU & warms up. After a few minutes, another process ' CrashReport' is using close to the other 100%. No crash report is generated (I think). Force quit both & everything cools down. Tried AFP and SAMBA. I can still connect to QNap with their web app.
2) Can no longer mount my iMac. Same situation as the NAS. Screen sharing doesn't work either.
3) Can't connect to my USB/400/800 Lacie Rugged backup drives over USB anymore but connects okay over firewire. Didn't like firewire since there's a history of dropped connections while connected. Anyway,
3) Some programs are either not working or causing grief. For example:
DROPBOX ( 1.4.17 and 1.5.10): App won't launch, but runs CPU to close to 100%. Not showing on menubar either. Force quit & every things okay.
PIXELMATOR (2.1.1): Crashes immediately on launch. Crash report is offered.
PLEX (0.8.5): Launches okay but find about 30 'Python' processes running and both sides running close to 100%. Python processes keep running after Plex shut down. Reboot and everything back to normal.
SUPER DUPER (2.6.4): Beachballs, 'Netauthsysagent' rears it's ugly head.
VLC (2.0.0): Bounces in the dock, drives the CPU to close to 100% but doesn't open.
FLASHBACK RemovalTool: Won't launch. Saw an extra drive in DiskUtility, some FlashPlayer installer so thought I might have an issue so thought I'd try this. Won't run.
4) DiskUtility Tool won't let me RepairPermissions on my HDD, button greyed out.
As I mentioned, everything worked great under SL. I suspect there might be an issue with the OS on a different drive from the 'Users' drive in ML but have no idea for sure. Tried to figure this out on my own but I'm kinda simple once things get technical for any help or 'next step' is appreciated.