I have mint 13 mate .
I have re edited this post to give more relevant info
My problem is when i browse through different directories on my pc and on networked pc , using icon view the look of the icon is different.
on my pc for example , pdf come up showing a preview of whats on the 1st page. On the networked pc be it linux or windows the icons show correctly.
I installed to virtual box LMDE and xfce-mint and both display this.
Ok was so silly as to be laughable, sometimes cant see wood for trees.
Helps to retype your thoughts as i did above, and realised what the issue may be.
file manager /edit/pref/preview/show thumbnails never
this was set to thumbnails for local files and seems is default for a new instalation