MAXSTRING Error when stream property data is too big

We ran into a problem with [isc.rest](http://isc.rest/) using streams to save attachments. It seems like its using the JSONExportToString by default if a property is a stream, and then giving a MAXSTRING error if the stream is too big.

This is the error we are getting when the steam data is too large:

{
"errors": [
{
"error": "Error #5002: ObjectScript error: %JSONImportInternal+100^.......",
"code": 5002,
"domain": "%ObjectErrors",
"id": "ObjectScriptError",
"params": [
"<MAXSTRING>%JSONImportInternal+100^......."
]
}
],
"summary": "Error #5002: ObjectScript error: <MAXSTRING>%JSONImportInternal+100^......."
}