Have you tried other fonts? Have you tried using fonts via Photoshop directly - without going through a 3rd party manager?
Yes i've tried other fonts, system fonts are not affected seems to be new ones which have been installed and have tried fonts directly through photoshop same issue.
The only thing i haven't tried is uninstalling and re-installing the fonts.
What about other apps, how do they display the same font?
Cheap fonts can often have poor kerning tables, which may be another factor.
I will try other apps today and see how they display. And report back if any issues.