ReSharper's code styling provides many more options than Visual Studio's code formatting, which is fantastic. In a default install of ReSharper and VS 2005, both code style (R#) and code formatting (VS) are turned on. Depending on how code is inserted, different code formatting will be performed. For instance, pasting will result in VS code formatting being applied. Completing a statement (; or }) will result in R# code styles. CTRL/ALT-F will apply R# code style. CTRL-K-F will apply VS code formatting.
Ideally R# should synchronize its formatting with VS where there is overlap. If this is not feasible, then simply disabling Tools... Options... Text Editor... C#... Formatting... uncheck first two checkboxes.