Your problem is that U-boot is linked to the wrong address (0). Instead it should be linked to the position, where you intend to run u-boot (in SDRAM) I know Wolfgang Denx diesnt like the idea of running U.boot from RAM, but you cannot run from an SPI flash, have to copy to RAM first, and the SDRAM on AT91RM9200 is located at 0x20000000 and above.
The prinout you see, is not from U.boot. It looks like a customized version of "dataflashboot.bin" It "bombs" after dataflashboot.bin has loaded u-boot into SDRAM and jumped to it starting point.
Since it is in the wrong locatgion, all the constant string pointers are off, and really only points at '\0' characters, so any attempt to printout data will fail.
If you are using Dataflash to store u-boot, you can read this as well. http://www.koansoftware.com/it/art.php?art=90 HTH