Postgresql – How to get PostgreSQL to not advance sequences when COPY fails

I'm importing CSV files into a relatively simple PostgreSQL database. (The CSVs are sometimes created manually from information in a book, sometimes created from spreadsheets with a little massaging via scripting.) I do it in small batches to make sure things are going ok, and I've noticed that when COPY fails, it doesn't roll back the sequence attached to the column in the table. (Note: I am importing via pgAdmin.)

For example, let's say this is my table:

TABLE
------------------
id | data1 | data2
------------------
1  | abc   | def
2  | ghi   | klm

Then let's say I try to import two more columns and it fails. I fix the error, and then the import succeeds. I'd expect the table to look like this:

TABLE
------------------
id | data1 | data2
------------------
1  | abc   | def
2  | ghi   | klm
3  | nop   | qrs
4  | tuv   | wxy

Instead, it looks like this:

TABLE
------------------
id | data1 | data2
------------------
1  | abc   | def
2  | ghi   | klm
5  | nop   | qrs
6  | tuv   | wxy

The tables all rely on each other (i.e. pretty much every table has a FK pointing to the ID of some other table), so if the IDs stay predictable, my data entry job gets a lot easier. If not, I have to keep double checking the IDs when I finish a section.

Is there any way to prevent this behavior?