Image Fragment size 102400 causes backup to fail with error 24 (socket write failed)

Friends,

Master 7.5.0.4 media 7.5.0.4 client W2K8 running 7.1.0.4 snapshot backup of a an area that receives the dump of 1TB everyday.

media server has built in 3TB storage - so basic disk storage unit with maximum no of streams set to 4 and fragment size 10240. 

strangely backup runs and soon as it hits 102400GB fragment size it fails with error 24 socket write failed. i have changed the fragment size to 512000 and its been running happily. 

any suggestions would highly be appreciated.