am335x u-boot fails

Hi!
We designed custom single-board controller around am3352 SoC. We uses NAND chip by Micron as general storage.
At first generation of design there was a MT29F4G08ABADA (4Gb ~ 512MB), and everything was fine.
We used u-boot build "freezed" at tag 2013.07 with some changes concerns our board, and
left it "as is" for a years.
But now we need modification with more disk space, and we decided to use MT29F16G08ABABA chip (16Gb ~ 2GB).
Suddenly ( :-) ) new board began to fail with this chip! Some investigations... and I (I am programmer in our workgroup) see,
that old u-boot failed at NAND detection. And there was huge code for the 3 years, including ONFI NAND support. And also
linux like Kbuild configuration, driver model an so on.

Something else... We use 2 builds of u-boot:
1. "Fabrication" (in other words "debrick") build, that boots over dhcp/tftp, and automaticly writes NAND partitions from MLO to kernel.
2. "Main"-standalone build, that boots from NAND.

Ok, I got fresh u-boot clone from denx.de , dragged our custom code to new source-tree, and now we have:
- "Fabrication" build - seems works fine, and I can see how it processes at console, there are no errors, except messages like this:

CACHE: Misaligned operation at range [81000000, 81059672]

- NAND chip detection - OK;
- u-boot "nand info" command, it seems, shows correct:
=> nand info

Device 0: nand0, sector size 512 KiB
  Page size       4096 b
  OOB size         224 b
  Erase size    524288 b
  subpagesize     1024 b
  options     0x4000000c
  bbt options 0x       0
- "nand write" operation reports "OK";
- nand read partition ok, and md shows correct hexdump (at few start segments that we can check by eyes)
But after debrick.scr script execution, which ends with "go 20000;" (ROM code address, isnt?)
We have:
## Starting application at 0x00020000 ...
prefetch abort
pc : [<00020004>]          lr : [<8ff700b5>]
reloc pc : [<f08b1004>]    lr : [<808010b5>]
sp : 8ef44cf8  ip : 8ef44ad4     fp : 8ffb69e0
r10: 00000002  r9 : 8ef4eed8     r8 : 00000000
r7 : 8ef96330  r6 : 00020000     r5 : 00000002  r4 : 8ef96334
r3 : 00020000  r2 : 8ef96334     r1 : 8ef96334  r0 : 00000001
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32
Resetting CPU ...

Any suggestions?
Thanks for help, ideas... right questions.