I just came across an article that describes a problem with Ubuntu 12.04 DNS resolving. If you use Ubuntu 12.04 and have problems with textures / sculpts / mesh not loading or loading slowly then you may want to check this out.
Of course there are several other possible ways that these problems could be caused so no guarantees.
Please also note that I don't use Linux myself. I'm just sharing this in the hope that it may help someone here.
http://java.dzone.com/articles/fixing-intermittent-dns