Impress: table formatting is lost on copy paste

When I copy paste a table in Impress, the format of the cell content is changing.
This can be annoying especially when I copy paste a table and the values suddenly do not fit into their cells and a line break is triggered.

I’m using LO 4.4.2.2 on Ubuntu 14.04.2
Linux 3.13.0-32 x86_64