Memory stick question

A few weeks ago I bricked my PSP attempting to use the 2.71 downgrader. I've since got a new PSP running 1.5 FW and new memory stick etc.

If I format my old memory stick from my first PSP (that had the .tiff and other downgrader files on it) will it be ok to use? Or will it somehow have traces of the downgrader stuff on it?

Maybe I'm being over cautious, I just can't afford to risk bricking my new PSP and could really use the extra 1gb memory stick space!

It was the Sony MS that came with the giga pack.

Well, after you've formatted the stick there's nothing left on it so it should be alright.