RCTgo

Playing RXT3 Update 2. all is well untill around year 25 when my park is nearly full of rides and shops etc. I try and add a ride to the park (pre built ride) when the ride is in place it takes around 3 seconds and the game cuts out with "an error has occured and rct3.exe has had to close" I thought this was me doing something wrong so I made a new park again in sandbox mode, I used all pre built rides, again around the year 25 (this game lasted longer than last) when adding a new ride (doesnt matter which) after a few seconds the game cuts out and same message occurs. I am using no custom scenery and have downloaded no extra packs or rides or themes. I have updated my Nvidia forceware graphics driver to the latest stable version 93.71 I have updated Direct X and its no different.
I have also changed all the graphic options to the lowest possible, no 32bit colour, no anti aliasing, no draw distance and all the detail / scenery settings set to 0. I have also used the ".dat.bak" Again the same thing happens. I have posted my DXDiag at pastebin...

http://pastebin.com/899084


Does anybody have ideas on what the problem could be and what I could try next?
Thanks in advance