UNREAL SPECCY - impossible open TRD files

[VELESOFT]

Why is impossible in UNREALSPECCY open some short TRD images ?
For example if you make clear TRD image, format disc and save small BOOT file and apply TRDCUP utility for resize TRD image, then unreal speccy emulator show error message and not open this TRD. But TRD images with lenght 16kB work OK. Then if UNREAL SPECCY support work with small TRD images, where is problem ? Any minimal size of TRD image ?

See also thread about TRDCUT utility:
http://zx-pk.ru/showthread.php?p=575174#post575174

[SAM style]

I think, minimal size of TRD for Unreal is 4Kb - one track. "Correct" size is n*4Kb.

[psb]

I guess that cutted TRD is not a standart thing. so, you can not rely that it will work anywhere. why it doesn't work in US - you can find the answer in US sources.