Some reading... and a few questions to answer to give someone enough information to try and help

Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037

What is a CODEC... a Primer http://forums.adobe.com/thread/546811

What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037

.

Report back with the codec details of your file, use the programs below

.

For PC http://www.headbands.com/gspot/ or http://mediainfo.sourceforge.net/en

For Mac http://mediainfo.massanti.com/

.

http://blogs.adobe.com/premiereprotraining/2011/02/red-yellow-and-gree n-render-bars.html

.

Once you know exactly what it is you are editing, report back with that information... and your project setting, and if there is a red line above the video in the timeline, which indicates a mismatch between video and project

.

More information needed for someone to help http://forums.adobe.com/thread/416679

.

Some is general about your computer and OS, some is specific to video editing

.

Build a Configuration file http://www.piriform.com/speccy

.

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)

.

Windows Indexing is BAD http://forums.adobe.com/thread/676303

.

While in Properties, be sure you have drive indexing set OFF

-for the drive, and for all directories, to improve performance

.

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

.

And the EXACT type and size of file that is causing you problems

-for pictures, that includes the camera used and the pixel dimensions

.

Plus Video-Specific Information http://forums.adobe.com/thread/459220

.

Read Bill Hunt on editing a VOB/MPG file http://forums.adobe.com/thread/464549

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

.

Work through all of the steps (ideas) listed at http://forums.adobe.com/thread/459220

.

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

.

Also read file troubleshooting http://kb2.adobe.com/cps/407/kb407928.html