[sqlite] Can't Open Database File

[Drew, Stephen]

Hi there,
 
I am having a problem with accessing my SQLite database.
 
I have a certain number of worker threads that access the SQLite database,
protected by a critical section.
 
The database is already open prior to this.  Each thread attempts to insert
a row protected by the critical section.  This works fine for about thirty
rows, but then I get a "Can't open database file" error.
 
Does anyone have any clues to what might be going on?
 
Many thanks,
Steve