Heres a pickle. Image Displays a Black streak

Hi,

we are having a problem here with our logo corrupting in excel.
we have a number of proformas we have used on Excel for years, with no worries. the main machine is a mac.

this afternoon we opened up an excel file we had been working on with the logo in it, and the logo was damaged.
the logo itself is black and white and is about 3cm x 12 cm. when we open an excel document containing the logo the bottom 1cm looks like the white areas have been turned black and the white areas are dotted with black.
basicly it looks like something has corrupted the image. even files created years ago now have a corupted logo. it also prints with the black mark across the bottom.

At latest scan today computer was virus free.

we emailed an excel file with the logo in it that we had not opened on the mac to another computer (pc) and it was ok. then we emailed a file we had opened on the mac but not saved, and the image was corrupted.

has this ever happened to anyone? and do you have any thoughts? we do not really want to replace the logo in every file.
i was thinking that maybe the source images is corupted, but i cant figure out how to find the original source image, and i am not sure this will help because excel seems to store image information within the file because the images go with the file when you email it around.

Thanks in advance!

Glenn

it stopped doing it this morning and everything is back to normal.

we did a full restart of the server yesterday, and it did nothing.
after back up last night all was well.

Who knows.
if this has happened to anyone else i would be curious to know why.
Glenn