I just purchased a e250 and I Rockbox'ed it, how big can I go with the micro sd card?  Here's the version info: 

 Product Rev.: PP5022AF-05.51-S301-02.24-S301.02.24A-
D
Base Code: 05.51-S301-02.24-S301.02.24A-D
ODM Ver.: S301-02.24-S301.02.24A-D
OEM Ver.: S301.02.24A-D
Build Type:
-D
Build Date: 2007.12.24
Build Number: (Build 32.10) 

 Thanks.

Marcus