aristellier

Help please!!! I have Inventoria and Expressinvoice and have done for the last year. Running them in sync has always been hit and miss but seeing as I only have a small business I've managed with it. Then this week a new thing happened, I can open inventoria and do what I want and all is Ok. I can open Expressinvoice and do what I want and all is Ok. But if I open both and try to sync then my computer locks out and I get a screen message which reads; "You need to restart your computer. Hold down the power button until it turns off, then press the power button again" Also I can't do back-ups!! I've tried contacting NCH who said they would try and replicate this problem and get back to me in a few weeks!!! Any ideas????