This was the problem:

Marking Dialog ..
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* $dll: unable to open 'C:\mIRC2\dcx.dll' (line 566, dcx.mrc)

But the dll is still here. This appened only with this dll and my computer. I have tested DCX on Win XP and Pentium IV 1.6 GHz and it work.
Are this problem solveble with future version of this dll? shocked