Well i went to my frien ds house to play some halo and recovered my profile at his house (xbox360 fyi)
I got home and didnt bother connected to Live becuase i didnt want to bother recovering my profile again so i just played with my profile offline. I played through the last couple missions on WaW on Hardened and beat the game 160 more achievment points... yay.

BUT then i wanted to show off my great new gamer score in the 5 digits by signing back onto Live. Xbox deleted my offline achievments and left me where i was before.
Is there a way to get my achievments back?
Those levels were pretty darn hard...

Not that I know of, same thing happened to me with Gears 2. If you want the points looks like you'll have to play the levels again.

i was hoping that i would just turn the game on again and it would notice that the levels have been beaten with my profile and just boost me up with my rightfully earned achievments :/

I don't think this is solvable unfortunately. I think it's because the severs detect only one profile at a time, so when you recover it it doesn't merge the two together. Stupid system, but they might sort something out with this new "holy hell, I'm a Wii now" "update". I also hope hey have the ability to reset gamerscore/achievements, but that's another barrel of fish.

B4D 9R4MM3R:
I also hope hey have the ability to reset gamerscore/achievements, but that's another barrel of fish.

They have the ability to remove games with 0 gamerscore from your profile/history, but that's the only difference I noticed.

On the plus side, they didn't mean anything and are utterly pointless. So in effect you've lost nothing.

Is anyone really impressed by someone else having a high gamerscore?

welll hopefully i only have to play through the last level and not the two before it.
then ill get all achievments i lost o.o
what a waste of time....

Yeah. Playing games (and having fun?) is such a waste of time. <.<

galletea:
On the plus side, they didn't mean anything and are utterly pointless. So in effect you've lost nothing.

Is anyone really impressed by someone else having a high gamerscore?

I believe my gamerscore shows how much of a none life I have (17246) and I wouldn't have it any other way. Gamer for life. =]

I've heard that if you have offline achievements and recover your profile they get deleted, not sure if its real though, sadly you're most likely gonna have to redo them.

CosmicStorms:
I've heard that if you have offline achievements and recover your profile they get deleted, not sure if its real though, sadly you're most likely gonna have to redo them.

They don't get deleted, its just that your online profile, the one without the achievements is saved over your offline one with them. So the only way to get them back is to either do the levels over, and if you don't get them then, delete the save that says you ever beat them in the first place. This has happened to me with COD 3.

I'm not 100% on how the system works on XBox LIVE, but with achievements and stat tracking on Steam you have to be in online mode for the Community to recognize any changes. This is because all achievements, stats and play time is recorded by the Steam servers themselves. Chances are that it's a similar system with LIVE. The only way for it to record your "gamerscore" thing is for your profile to be logged in at the time to the servers can register the change.