[Vitaly]

You mean, "attachments rewrite" vbseo options? I din't checked it at all, because don't use it (that option is off in my vbseo config).

Anyway, check twice, that your nginx config has separate "location" for thumbnails, and that this location stays before vbseo location. For example, you can temporary add deny rule for thumbnails location, to check that it's really catched.

vbseo php code should NOT be called for direct thumbnail links. Or you'll get no benefits from this mod.

Mod idea is:
- minimise php calls (no calls for thumbnails at all)
- minimise useless data transfer (can make sense for big attachments)