Parsing issue with 1e12

Hi Hat and Yhc people (and I guess nhc people as well),

Both GHC and Hugs parse 1e12 as a number, but Hat and Yhc don't.

For example, test = print 1e12 gives:
yhc: -- during when renaming
Error: Identifier e12 used at 7:15-7:17 is not defined.

I have also been told that Hat leads to an error.

So:

1) Is this an error, what does the Haskell spec say?

2) Should the parser be fixed in all the right places? (does this
impact Colin's hpc as well?)

Thanks

Neil