Problem with reloading the MI4 file

[gumhead]

Hi there.....I am having trouble reinstalling rockbox. I have been trying to reload the mi4 file as my sansa e250r tells me it is unable to locate this file. I have followed the directions for entering the recovery mode and have placed the mi4 file into the partion. When I disconnect it tells me Load main image failed -Switch to recovery. I go through the recovery mode again and find the mi4 file I placed in the partion has dissappeared . I have replaced this file several times all to no avail.
Any help would be helpful.
Regards

[Chronon]

You may find some helpful advice here: http://www.rockbox.org/twiki/bin/view/Main/SansaE200Unbrick