Creating a big file over the text editor generates a checksum error

[cdamken]

Steps to reproduce:

1.- Create a New file over WebIU + -> Create Txt File
2.- Paste a big text document (in my case more than 1000 lines of text)
3.- Close immediately the file.

Wait.

4.- Sync-client says in the activity tab (Not Synced)
The downloaded files does not match the checksum, it will be resumed.

@tomneedham @jnweiger