I've never experienced these errors, but I'm posting because I do heavily use hash tables.
Currently, I have 21 hash tables loaded. Together they have a size of about 900 slots, and about 7 times as much items. Most of those items only contain a single integer value, but a lot of them have longer values. One of the tables belongs to a theme system, and is accessed on almost every event, 15 of the tables belong to an experimental stats script I wrote, and some of those are accessed even more often. The rest is mainly used for settings and are usually accessed when opening a dialog or something like that.
Seeing that my hash table "traffic" is rather intense at moments (I have experienced lag on occasion), but I haven't seen the error, I don't think hash tables are without question the cause (but ofcourse I'm not ruling them out).
I usually don't run mIRC for more than 15 hours, but sometimes I run it for several days, but I haven't experienced any increased lag.
DLL wise, MDX is usually loaded by several scripts, and sometimes a DLL for a specific function, which isn't loaded long. I don't use dock DLL's etc.
Hope that helped.
