Can’t import old entries to my new blog!

Hello!
I’m having problems importing all the entries from my old blog (on another server and domain) to my new blog. I’ve managed to backup the data via the built-in backup in WordPress. So, I have the .SQL-file on my local harddrive, but when I try to import it into my new blog via phpMyAdmin there is an error message:

INSERT INTO wp_post2cat
VALUES ( 315, 217, 16 )

MySQL sa:
#1062 – Duplicate entry ‘315’ for key 1

I get the above message when I import entries from my old database to new one (containing a few entries already).
If I delete all entries in my new blog and try to import again, I get the following error message:

—-START URKLIPP—-
eNodzsFSgzAABNB7vmIPPUKapKCQG9JYmQkFCVbHS0uVQWYQELS239aDn+QvSL3u7OxblWVJJhFy
hAJarSU4BBY+MfkUnwkJN0ZiFr1KjB9NXwxjOdCm3tP+rbcOEPSKCupAMObM2WLOXHBPukK6Dpry
3Yc69piR+GTutYRDGRXOdlnu66K1ORuLoSqF3XQVeTAZEmMhWKl1bmGjJv2xbhEnz5HWAVzKSBoH
chJdem33DSfpXXrpWYm5LDuUQ9ft15HoYL2a3h7seuxsz3N9m5N//vf8s8ySFHlwoxWiW6inyOQG
u+9++1J8llU31OW4+wPl8kud
—-SLUT URKLIPP—-
—-START R?TEXT—-

ERROR: C1 C2 LEN: 1 2 39
STR: ?

CVS: $Id: sqlparser.lib.php,v 2.6.2.4 2004/03/05 18:52:54 lem9 Exp $
MySQL: 4.0.24_Debian-10sarge2-log
USR OS, AGENT, VER: Win MOZILLA 5.0
PMA: 2.5.7-pl1
PHP VER,OS: 4.4.1 Linux
LANG: sv-iso-8859-1
SQL: ???DROP TABLE IF EXISTS wp_categories

—-SLUT R?TEXT—-

SQL-fr?ga :

???DROP TABLE IF EXISTS wp_categories

MySQL sa:
#1064 – You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near ‘???DROP TABLE IF EXISTS wp_categories‘ at line 1

Please help me anyone!