Subscription System: Change hard coded currency

[bollman]

We've just installed this and it all works fine, except the value in our local currency (SEK, or Swedish Krona) is not displayed in the text field. If I enter a number and save, the next time I look at the subscription, the value is 0 (zero), but if I look in the database:
a:1:{i:0;a:6:{s:4:"cost";a:6:{s:3:"sek";s:4:"5.00" ;s:3:"usd";s:4:"0.00";s:3:"gbp";s:4:"0.00";s:3:"eu r";s:4:"0.00";s:3:"aud";s:4:"0.00";s:3:"cad";s:4:" 0.00";}s:6:"length";i:4;s:5:"units";s:1:"D";s:11:" ccbillsubid";s:0:"";s:18:"twocheckout_prodid";s:0: "";s:9:"recurring";i:0;}}
Which looks correct to me, at least
I have double and triple checked the edits in the php files, but can't see anything wrong there.
We're on 4.2.2 (brand new install, we're moving from phpBB).