I also remember that it used to give me recoverable errors. 9/10 when i quit. I don't remember how i fixed it, it's been a long time since then...
In another thread, you say that you are using the exec v40.68 which contains many bugs. I recommend you to install an exec bug-fix software, like the romfixes module of the Blizkick, (in case you already use blizkick or it supports your CPU card) SystemPatch or any other similar package.
Another thing that you should look at, is to try to install the MCPramlibpatch (It's inside the MCP archive) and increase the stack of the WW executable.