Strange Cursor Placement in Writer

Hi, I have the new version of portable open office. When typing a document the cursor seems to start somewhere different from where the word is typed. A bit tricky to explain, but as I complete typing a word and hit the space bar the cursor jumps out about a Tab Space to the right i.e. much further than the single space you might expect. Then when I start typing the next word the cursor and the letter appear where you expect them i.e. the cursor jumps back to the left. Also at the end of a sentence if I have a fullstop then the cursor remains between the last letter and the fullstop. Very disconcerting if you need to edit the file regularly?
thanks dave.P

p.s. did not have this problem with previous version - may have to switch back?

p.p.s. I was using the font Shruti. Do not experience the problem if I change to Arial or Times New Roman. If I open a new document and use Shruti I still get the problem. Strange.