Problem with sequences on a reload of a pg_dump file

To all,

We dumped our instance from a 7.4.2 instance compiled with a block size
of 32k running on OSX 10.3.3 server..  We loaded this dump on Fedora
2.6.5-1.358smp running postgresql 7.4.2 compiled with the standard 8k
blocks size.

My problem is that all the sequences were reset to start a 1. :-(   Did
I do something wrong as this has never happened before?  Also, can I
simply figure out what the  next value should be and manually update the
last_value column in each affected sequence?

Thanks.

--sean