The sources of immigration for Scotland seems to be a bit different. I can count the number of black people I've seen in RL on one hand. I've also seen very few Arabs, although where I live there are lots of Pakistani/Bangladeshi immigrants, and in other parts of Scotland there are a lot of Poles.

I can't say there have been any real problems with these groups, not on a national scale, or from personal experience. The local Paki's (corner shop for those wondering) was run by as nice a guy as you could hope to meet. On a wider scale, I also don't think there have been problems along the lines of those mentioned with Arabs, but then I guess they are different cultures.

The Polish are generally regarded as good, honest hard workers. The only problem is they tend to support Celtic.