Beta 2.0 Feedback regarding pasting more than 25 rows

It seems that when I try to paste or delete more than 25 rows of data it does not stick. When I refresh screen or leave page, it is not there when I come back. Is this a bug?

I tried the same at local machine, but it pastes rows correctly.
Does any javascript error occur when you paste more than 25 rows?
Could you provide a link to spreadsheet with a problem?