PRE7 is usually very stable so your problem is not likely to be solved just by upgrading to PRE9. You should first work your way through the tips in this article PrE Hanging, or Crashing - Some Tips and post back with the details requested. Don't forget to include the GSpot screenshot.
Insanity is hereditary, you get it from your children
In any event, upgrading will not likely solve your problems.
Version 7 was an extremely stable build. So, until you figure out what's going on with your system or your source video (using the steps Neale recommended), upgrading is most likely going to only compound your problems. Sorry.
You need to give more information for someone to help
Some specific information that is needed...
Brand/Model Computer (or Brand/Model Motherboard if self-built)
How much system memory you have installed, such as 2Gig or ???
Operating System version, such as Win7 64bit Pro... or whatevevr
-including your security settings, such as are YOU the Administrator
-and have you tried to RIGHT click the program Icon and then select
-the Run as Administrator option (for Windows, not sure about Mac)
Your Firewall settings and brand of anti-virus are you running
Brand/Model graphics card, sush as ATI "xxxx" or nVidia "xxxx"
-or the brand/model graphics chip if on the motherboard
-and the exact driver version for the above graphics card/chip
-and how much video memory you have on your graphics card
Brand/Model sound card, or sound "chip" name on Motherboard
-and the exact driver version for the above sound card/chip
Size(s) and configuration of your hard drive(s)... example below
-and how much FREE space is available on each drive (in Windows
-you RIGHT click the drive letter while using Windows Explorer
-and then select the Properties option to see used/free space)
While in Properties, be sure you have drive indexing set OFF
-for the drive, and for all directories, to improve performance
My 3 hard drives are configured as... (WD = Western Digital)
1 - 320G WD Win7 64bit Pro and all programs
2 - 320G WD Win7 swap file and video projects
3 - 1T WD all video files... read and write
Some/Much of the above are available by going to the Windows
Control Panel and then the Hardware option (Win7 option name)
OR Control Panel--System--Hardware Tab--Device Manager for WinXP
Plus Video-Specific Information http://forums.adobe.com/thread/459220?tstart=0
And, finally, the EXACT type and size of file that is causing you problems
-for pictures, that includes the camera used and the pixel dimensions
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037?tstart=0
What is a CODEC... a Primer http://forums.adobe.com/thread/546811?tstart=0
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037?tstart=0
For PC http://www.headbands.com/gspot/ or http://mediainfo.sourceforge.net/en
For Mac http://mediainfo.massanti.com/
Read Bill Hunt on editing a VOB/MPG file http://forums.adobe.com/thread/464549?tstart=0
Edit Vob http://premierepro.wikia.com/wiki/FAQ:How_do_I_import_VOB_files_/_edit_a_DVD%3F
Read Hunt on Using MOD/TOD files http://forums.adobe.com/thread/699990?tstart=0
Also, For Windows (not sure about Mac) This is aimed at Premiere Pro, but may help
Work through all of the steps (ideas) listed at http://forums.adobe.com/thread/459220?tstart=0
If your problem isn't fixed after you follow all of the steps, report back with ALL OF THE DETAILS asked for in the FINALLY section at the troubleshooting link