YUMI Multiboot Problems: FAT32: No GRLDR?

[Urfaust]

I have been attempting to make a multiboot usb using the automated program YUMI. I have created successful multiboot thumbdrive systems with YUMI before, but this time, no luck... The recovery programs/ISOs that I attempted to add were as follows:

Hirens Boot CD
Konboot (commercial)
T(A)ILS
TinyCore
Kaspersky Rescue 10
PING
RedoBackup
RIP Linux
System Rescue CD
Trinity Rescue Kit
Puppy Linux
Xpud

and two unlisted ISOs:

Knoppix STD (the latest version)
Privatrix (the latest version)

Now... Every time I try to boot up the multiboot USB from the BIOS this is what I get on my screen:

Try (hd0,0): FAT32: No GRLDR
Try (hd0,1): invalid or null
Try (hd0,2): invalid or null
Try (hd1,0): NTFS5: No grldr
Try (hd1,1) EXT2: No grldr
Try (hd1,2): non-MS: skip
Try (hd1,3): invalid or null
Cannot find GRLDR.
Press space bar to hold the screen, any other key to boot previous MBR...
Timeout: 5

Does anyone have any idea what I'm talking about, or know of anyway to resolve this? And if not, does anyone know where I could post this question to seek viable help? This is my dream multiboot, and I have no idea where to start or how to accomplish it - any ideas?

Thanks in advance for taking the time to read this.

[Rubberman]

What kind of device are you trying to boot? You say a lot about the software, but virtually nothing about the hardware...

[Urfaust]

A USB flash drive formatted to FAT 32 with 8GB of space. It's made by ScanDisk.