Can't restore my distribution DB postgres 9.2 backup into my staging DB postgres 9.3

Question

I keep getting this pg_restore: [archiver] did not find magic string in file header when i execute a pg_restore -Fc -U "username" -d "dbname" "filename".dmpon my staging DB.

These DB are running on two separate AWS instances with windows server 2008 for both environments(staging and distribution). The postgres version used on distribution is the 9.2 and the version on staging is 9.3.

I think this issue could be related to the fact that i get several pg_dump: [custom archiver] WARNING: ftell mismatch with expected position -- ftell used warnings when i execute a pg_dump -Fc -U "username" -w "dbname" > "filename".dmp on the distribution DB.

Any help is appreciated.