I did last tests with Memtest 1.09.
Commodore 128 really passed, even with CP/M Cartridge...
But when I started/reseted C128 with holding C= key - direct jump to C64 mode, testing VDC RAM produces error.
It during tests increments value to 15 and then displays error memory testing. Other tets after have no problem.
Results are placed here: http://www.mirkosoft.sk/memtest109.zip