Yes, the name changed to mirc.exe because there's now no longer a new 16 bit version.

I get the same memory leak and I believe it is due to hash tables because I do run a copy of mIRC for a bot (with no hash tables) yet it seems to be okay. Mind you the differnce between the two is many dozens of megabytes. The bot peaks at about 8MB averaging 4 - 5 while a script I use can chew up like 182MB!! on the odd occasion.