Hi Junior
That is really bad luck, on top of all the waiting!
Ok, first, if you are using a SD card, take it out and try the reboot process again.
Several people experienced problems with SD cards, specially with the ones sold with the Cybook.
If this resolves the problem, try to format the SD card with fat32 and try using it again to see if it now works well.
If this does not resolve your problem take a look into this post:
https://www.mobileread.com/forums/showthread.php?t=26323
Download the version of the firmware in it and try to install it - it’s supposed to be the version you already have but that formats your machine and installs everything from scratch (there is also a 538 version in the forums, but that one just works with the 64 Megs Cybooks not the 512 Megs ones, and I think your is one of those).
Let us know how it goes.
Best,