You are getting a merge conflict. Most likely cause is that you have added files to your mojoPortal.Web.csproj so it is different from trunk and when it tries to merge it has conflicts.
Best way to avoid this is to NOT add your custom files to the project. Build custom features in external projects and don't add your custom skins to the project.
If you right click your mojoPortal.Web.csproj file and choose Tortoise svn > Revert it will remove your customizations from the project file.
Hope it helps,