We seem to have went from the No such nick error, to the possibilty that you are blocking a certain type of file from being received, If it is the latter this may help
I believe you might find you are blocking certain filetypes from being received. To temporarily stop the type being blocked you can type in any open window
/dcc ignore off
by Default the ignore should turn back on in 3 minutes, this solution is temporary.
For a permanent fix, you go into your mIRC options, normally accessible by holding down the ALT-key and pressing O-key (letter O) and in the Section called DCC look for a subsection titled Ignore, you can make permanent changes in there
ScoT
#mIRC Undernet