modding problems in minecraft

Depends on the mod, but it could be the mod is not updated for 1.1 or you are a missing a prerequisite (some mods even require Java 7). Also in rare cases mods just don't work on your system. For some reason I was unable to run More Ores for quite a long time despite have all the pre-req's and the proper version.

the mods i've tried to install said they were the 1.0 (when i was on that) and 1.1 but still end up breaking the game

I know ScotTools breaks Millienaire, but on previous versions it did not. Which mod is it? Your best bet is to slowly add in the mods one at a time and see which one breaks everything.

the one i tried to install was a graphics mod can't remember the name by heart

the one i tried to install was a graphics mod can't remember the name by heart

FreakShowScot

A texture pack? or something like the water shader? The water shader doesn't work on my PC (I haven't tried the newest one), but the author stated something about it not working to well with ATI cards (which I have). It could be something like that though.

Did you delete the folder META-INF in minecraft.jar before installing? If you don't MC won't start.

i got it i didn't delete the META-INF folder cheers