MS SQL Server

I have seen several recent comments saying that MS SQL has stability
problems. I have some friends using MS SQL Server v7 and they say
they haven't had any problems. They indicated some previous versions
had problems, but since the introduction of v7 things have been
running well.

Without starting a landslide what types of problems have been
experienced and with what version?

Thanks
Warren Eddy
Consultant for National Tube Form LLC