Small question about HDR-workflow-051 enfuse warning, can someone please help?

[lifeartpixels]

When i use the script (which seems to work just fine..) i always see these messages popping up in cmd.exe , can someone explain what this is and if i should change something?
enfuse: warning: no usable resolution found in the first image "frames\A.......jpg";
enfuse: warning: will use 300 dpi
Am i not getting maximum results at the moment? or are these no problems and is everything working fine as it seems to?

One more question, how do i get the script to write and work with tif files? I assume this would up the quality compared to jpg's, or am i wrong?
I edited '.jpg' to '.tif' in in all the script files, but i get a error that .tif is an unsupported format..is it really unsupported? i read a post on this forum before that said it was possible to change from .jpg to .tif...

Thanks for your replies guys, appreciated!