NNTP false bogus commands?

I was checking my logs and saw this.

Feb 26 19:04:01 bbs synchronet: srvc 0052 NNTP [DOVE-Net.Synchronet_Announcements] cmd: GROUP DOVE-Net.Synchronet_Baja
Feb 26 19:04:01 bbs synchronet: srvc 0052 NNTP Throttling bogus command sending client for 3 seconds

but on another connection

Feb 26 19:07:23 bbs synchronet: srvc 0051 NNTP [SpookNet.SN_PARANORMAL] cmd: GROUP SpookNet.SN_POLITICS
Feb 26 19:07:23 bbs synchronet: srvc 0051 NNTP [SpookNet.SN_POLITICS] cmd: GROUP SpookNet.SN_PREDICT

No error.

Not sure why this should be happening.