I've experienced this on dozens and dozens of posts. Here's three examples:
#1) @ 162d old:
a.b.mm@EFNet - REQ 55494
The.O.C.S02E03.The.New.Kids.On.The.Block.WS.DVDRip.XviD-TVEP
Search for either string on BinTube turns it up. The headers are there in Agent. Search for any of the text on Binsearch returnz zilch at 162d. Even a simple search like "new kids dvdrip" fails on Binsearch. Searching for similar strings though for other posts which are newer do show up on BS, so I don't believe it's a syntax issue, just the data is physically missing from the database.
#2) @ 201d old:
#a.b.mm@efnet - req 52348
North.Face.Expeditions.Between.Heaven.And.Earth.720p.HDTV.x264-PiX
Again, any search for these strings on BinTube turns op the post, so does an actual header pull from Giganews. Searching for any of it, even something simple like "North Face" or "north 720p" on Binsearch returns nothing
#3) @ 173d old:
www.Bin-Req.net Presents: #54813
David.Letterman.2008.07.15.Meryl.Streep.HDTV.XViD-YesTV
Also shows in BinTube and Agent. Nada with Binsearch. Even "Letterman Streep" fails BS.
...This could go on for hundreds of examples, but I think I've made my point, Binsearch's database is fubar'ed, BinTube's isn't.
I noticed this because I usually just use Newzleech to browse the groups I like with the >190d date range feature, but when it started giving jibberish results a few days ago, I started pulling the old headers with Agent, and when I saw something I wanted, I did a Binsearch for it to try and add it to alb.binz the easy way, and lo-and-behold, nothing showed up. So I checked the web interface for BS to make sure it wasn't an alt.binz issue and had same results, that's when I discovered that BinTube had the posts properly indexed.
Cheers