Hi Rick,

>If multiple MTDLL requests happen simultaneously VFP runs seperate runtimes files. VFP actually makes a copy of for Fox9t.dll and uses that internally (or more than one for that matter). The reason for this I would guess is that VFP is internally is not thread safe. The T runtime has provisions that takes all the critical stuff that VFP uses and sticks it out to thread local storage but it can't use the same instance just the same.
>

Correct me if I'm wrong, but I thought the copy of the runtime only applied to the single-threaded DLL. According to VFP Help:

Visual FoxPro makes it possible for the same vfp7t.dll run time to be deployed with multiple, concurrently called in-process .dll automation servers whether they are in same process/thread or not. The original vfp7r.dll run time creates a renamed copy of the library for each in-process .dll server running in the same process.