Hi Claire Walters,

It's OK to leave the spaces where they are needed.

There are 2 possible reasons why this may be happening.

Firstly, the QA space check doesn't always see things such as tags or returns so misinterprets the space before and/or after as being a double space.

You can turn this check off here in the project settings, and also under File>Options if you don't always work with projects:

The second instance is here:

This check will compare the Target spacing around tags with the Source spacing and alert you if it has been changed. Sometimes this is helpful/necessary. Other times such as when Source punctuation behaves differently to Target, it can be incorrect in the context. Thus it may or may not be useful to have this box ticked. 

These types of error message won't prevent conversion back to the original format document.

I hope this is the answer you needed,

All the best,

Alison