Unsupported Compression Format in Premiere 5.1

[Guest]

I have been using Premiere 5.1 for several years - forgive me for being so out of date - but only in analog. I have finally made the leap to digital but have stumbled across some problems. I capture fine through Firewire and Pinnacle Studio 9, but when I import to Premiere 5.1 I get told the file is of an
"unsupported compression format". Please help!!