i am trying to decompress a divx file ready to make into a vcd when i put it into virtualdub 1.4 it has to reconstruct the index file for this clip (watever that means) and i get these warnings

warning - virtualdub has reconstructed the index for this file ,but you have not specified rekeying in the extended open options diaglog.seeking this file may be slow!

i cannot open the file properly in tmpgenc it just comes up as a black screen ,wat do i need to do ?