Doesn't work against any of those effects. None of them target cards in any graveyard (Well, a flashbacked Recoup does, but the flashback mechanic itself does not)
Psychatog's removal is not targetted.
Flashback does not target the card itself while in the graveyard.
Twilight's Call is a "global" effect for graveyards. Non-targetted.
Mortal Combat simply counts, it doesn't target.
Ichorid doesn't target.
Basically it hurts Regrowth effects.
By Matt Caplan (Caplan) on Tuesday, February 05, 2002 - 10:56 pm: It stops anything that targets cards in graveyards. That should be enough of an explanation.
If it isn't, here is a fairly comprehensive list of cards that are at least partially shut down:
Anarchist
Animate Dead
Apprentice Necromancer
Argivian Find
Argivian Restoration
Ashen Powder
Auramancer
Breath of Life
Carrion Beetles
Cartographer
Cauldron Dance
Chainer, Dementia Master
Coffin Purge
Coffin Queen
Cremate
Crypt Creeper
Darigaaz's Charm
Dance of the Dead
Dawn of the Dead
Death's Duet
Decompose
Diabolic Servitude
Disturbed Burial
Elven Cache
Endbringer's Revel
Famished Ghoul
Forgotten Lore 
Gaea's Blessing
Goblin Welder
Gravedigger
Groundskeeper
Hakim, Loreweaver
Hanna, Ship's Navigator
Haunted Crossroads
Headstone
Hell's Caretaker
Holistic Wisdom
Hymn of Rebirth
Iridescent Drake
Junk Diver
Karmic Guide
Life/Death (Death)
Lin Sivvi, Defiant Hero
Lodestone Bauble
Malevolent Awakening
Midnight Ritual
Miraculous Recovery
Misinformation
Monk Idealist
Morgue Theft
Mudhole
Necromancy
Oath of Ghouls
Petrified Field
Phyrexian Delver
Phyrexian Furnace
Phyrexian Grimoire
Phyrexian Reclamation
Piper's Melody
Raise Dead
Rapid Decay
Reanimate
Reap
Recall
Reclaim
Recoup
Recover
Recurring Nightmare
Regrowth
Reinforcements
Relearn
Restless Dreams
Revive
Reya Dawnbringer
Scrivener
Shattered Crypt
Soul Exchange
Soul Strings
Steamclaw
Strands of Night
Sylvan Hierophant
Tortured Existence
Tragic Poet
Treasure Hunter
Undertaker
Unearth
Urborg Uprising
Victimize
Volrath's Stronghold
Zombie Cannibal
Zombify
I apologize if I missed any.
By Matt Caplan (Caplan) on Tuesday, February 05, 2002 - 10:57 pm: It does not stop cards that do not explicitly target cards in graveyards, including the entire mechanic flashback, Twilight's Call, Living Death, Yawgmoth's Will, Replenish, Tormod's Crypt, Mudhole, etc.
And yes, I do have too much time on my hands.
~Matt
By Rico Jones, Elfman Extraordinaire (Rico) on Tuesday, February 05, 2002 - 11:52 pm: Dude, that list is really long. Please tell me that wasn't off the top of your head. (Rico scratches his head and thinks for a moment) Even if it wasn't you still have too much time on your hands.
By Rico Jones, Elfman Extraordinaire (Rico) on Tuesday, February 05, 2002 - 11:55 pm: Supposing you used a search function somehow, unless you copy and pasted, that is too much typing. Wow. I guess this is what sets BDominia apart from the rest. Even if you copy and pasted.....
-Rico's in awe
By Voice of Reason on Wednesday, February 06, 2002 - 02:12 am: Does ground seal stop tormods crypt? Crypt targets the entire graveyard at once I think rather than specific cards.
By François Laroche on Wednesday, February 06, 2002 - 08:47 am: Tormod's Crypt
0
Artifact
T, Sacrifice Tormod's Crypt: Remove target player's graveyard from the game.
The Crypt targets a player, not cards in a graveyard. So no, Ground Seal doesn't affects Tormod's Crypt
By Liam (Liam) on Wednesday, February 06, 2002 - 04:23 pm: It's very nice-looking in foily though
By BWM on Thursday, February 07, 2002 - 04:08 pm: and it sux anyway...
By jon on Monday, February 11, 2002 - 06:23 pm: anyone want 4 ground seal 1 foil