With PRE 8 when I import AVCHD video files from HDD, files that are less than 30 MB, they will import. When I try to import larger files, 4 GB, PR8 locks-up and I get "program is not responding" and you have to shut it down.
My Laptop is
Windows 7 Home Premium
Dell Studio 17 Laptop PCS17HN
Processor Intel® Core™ i7-720QM Quad Core Processor 1.6GHz
6GB, DDR3, 1333MHz, 2 DIMM
(2) 500 GB Dual SATA Hard Drive (7200rpm) – with lots of space
1GB ATI Mobility Radeon™ HD 4650v + TV Tuner
17.3” HD+ (900p) Bright LED Display with TrueLife™ and Camera/Facial Recognition SW
Dell Wireless 365 Bluetooth Internal (2.1) [$20.00]
8X DVD+/-RW Dual Layer Drive8X DVD+/-RW Dual Layer Drive
+ Roxio Easy CD & DVD Burning - Enhanced Burn/Authoring
Soundblaster X-Fi Hi Def Audio - Software Enabled
If you're importing to your second hard drive, see if it's formatted NTFS or FAT32 (as they come from the factory) . FAT32 drives have a 4 gig file size limitation.
Converting the drive to NTFS (which you can do very likely without losing its data) will resolve this issue.