Synchronisation problem in Line Input

I am using the Calc Spreadsheet on a Macbook 10.6.8.
I am typing in text (wordwrapped) in a cell often with several lines.
If I use the delete key or use the left arrow in the line input window
(the small window above the main cells window), its position on the
type varies - either right(correct), centre or left.
This seems to be a bit random. It can become difficult to delete a single
letter because I am never sure which letter will be deleted.
Supposing I type these numbers - 123456. Normally I would click to the
right of 4 to delete it. Sometimes I have to click in the middle of 5 or
on the right side of 5 to delete 4. All very confusing.
I am using “courier” as I thought maybe a fixed font spacing may help.
Any ideas you have would be appreciated. Thanks . Maurice.

Which LibO version are you using?

Please edit your question to include a screenshot (or link) showing cursor position when editing. Thanks.

Although you are using Courier, this sounds like the mis-aligned cursor in proportional font problem for MacOS as reported in bug fdo#48402.