Font issue Draftsight / Mountain Lion

Hi,

I recently installed Draftsight V1R4 and it doesn't run as it should. But actually the problem didn't start with installing V1R4, but with upgrading from SnowLeopard to Mountain Lion. Then I noticed Draftsight didn't recognize Arial Narrow anymore, so I switched fonts. No big deal. But now, since updating Draftsight to V1R4, it runs really slow when I try to do anything with texts, especially when it's part of a component. 

I checked my video card (because multiple forums advise to upgrade the driver) but it should work just fine. I'm running DS on a iMac 27inch/2,66GHz Intel Core i5 processor/4GB RAM/ATI Radeon HD 4850 512MB video card/ OSX Mountain Lion 10.8.5.

Is anyone familiar with this problem? Does anyone knows the source of it (is it a font-problem? or a Mac-problem?) or better, does anyone knows the answer? THX!