I got a 2004 wrx. Normally around start of summer or during winter my key pad plays up. Lastweeks I had the same prob mate. I went work with my brothers car cos I could not start mine up. I go home afte work and it started up. Try locking it and unclocking once or twice and you prob be able to start it up. It's a common problem with the security alarm o was told by Subaru at one point as well.