Cant flash from SD CARD!

[ModmyPPC]

Guys I can't seem to flash from my sdcard.

Ive done it a million times.

But when it goes to tricolor screen it tells me that No image file was found or something along those lines. It passes by very fast and I can't catch it.

The file is not corrupt because I just flashed it through my computer.

I want to be able to flash the rom just in case I can't get to my computer or the phone wont boot.

Ive always had my current rom on my sdcard just in case I need a re flash when Im away or something. its very convenient but for some reason I can't flash sharkies 1.3 sprint rom.

This weekend I had to flash a year old rom because it was on my sisters computer and it pissed me off to no end.

Can anyone help me?

I tried removing the files and redoing it but for some reason it simply wont flash the Rom!