'inappropriate memory usage from the scripts' what aload of

looks like your web host is copy and pasting a standard reply meaning, there is an issue but we aren't going to do anything about it.
These types of errors I have seen before and are usually a server issue of some kind, however I know from personally experience that trying to track down what is wrong with the server can take hours if not days and often just reinstalling the OS is the fastest solution. However, often reinstalling IIS and making sure you have all the latest drivers and updates can fix the issue.
Web Wiz Forums just uses standard ASP, how memory allocation is dealt with is handled by IIS's application pool and the forum software has no control over this.
Web Wiz Forums code is very cleanly written with any objects and database connections released as soon as they are finished being used. Your host blaming the script (actually ASP is an application not a script) is incorrect. If Web Wiz Forums was badly written then allot of people would have issues. We even had a competition run a few years ago were if anyone could find somewere where an object was not released or a database connection was not closed they would win $100, however no-one was able to find any.
The amount of memory used depends allot on how many visitors your forum gets and the database used.
Typically if you have a forum like this one with around 50 to 100 active users after about 5 hours IIS will use around 150MB.
If you use SQL Server then the amount of memory depends on how big the database is, but after a few days any SQL Server database can be using over 1Gig of memory. To prevent this you can set the maximum memory SQL Server uses to the same size as the database + an extra 50MB or set the database to auto-close thus freeing up memory (I would use a combination of both if you are limited on memory). This reduces the amount of memory used by SQL Server.