Restart pc?

[stbaskets]

I had trouble with the latest bug build, this one Shareaza_2.5.2.2_Win32_Debug_r8618_2010-05-28.exe and I wanted to go back to the previous one. When I did I kept getting a message telling me I had to restart my pc because of a previous install. I have never had this happen before. Is it a new feature or a glitch?