Backburner Error: TIFFAppendToStrip

Hi,

This is a new one to me.

I am rendering a number of frames as TIFF files, as single frames. 
Occasionally, more frequently lately, I get this error message:

Tif Error: TIFFAppendToStrip - (network name)\X.tif: Write error at scanline 
539

I am using an older third party GI solution, but this is a new error since I 
upgraded to Max 7.0

Any help would be appreciated.

Thanks.