login failed in build query in ssis

HI

my data source is OLE DB source then I am create connect manager here test it successfully connected.

then i am going build query throw in error login failed.

1.today morning i am worked same connectiona one OLE DB datasource.evening same packaged i am created another OLEDB source error even 1st OLE DB connect also failed now(Morning created)

2.i am checked same user name and password with my data its working fine

3.if create new SSIS project its working fine.(same server and user name and password)

4.i am tryied 3 to 6 time my ststem restart still i am facing same problem.

Note:server and username and password all correct i checked lot of time.when i create new project(visual studio-->file-->new-->project..)its working good(same server and user name and password)

and also i double checked another system its working fine.

anybody faced this type issue please suggest me.

how resolved this issue..becoz..i am aready created lot of work.

Thanks

Aruna