Dropbox sync and metafiles

I am using dropbox to synchronizing two computers using these configurations:

Version Control
Mode: Meta Files

WWW Security Emulation
Host URL: .mydomain.com/mygame.unity3dme.unity3d

Asset Serialization
Mode: Mixed

And the problem is:

Every ‘first’ time i open unity in each computer after a modification is done, Unity will import every single asset(at least i think it is every single asset). It takes almost 15 minutes in one of the computers to do so… Is it expected? Or i did something wrong?

One uses Windows 8 and the other uses Windows 7 if this changes anything…

The asset importing happens because everyone uploads their local cache into dropbox.Change the settings in dropbox to exclude the Library-folder in your Unity project, so everyone has their own - correctly referenced - local cache. While you’re excluding folders, consider excluding the Temp-folder, which only appears during Editor runtime. All files in Temp should be locked by Unity, but you never know…

Edit: What iwaldrop said is also a good idea: use proper version control. If you find github to be too confusing ( I did), use SVN.