Just realized that the Linksys WRT54G V5 router that I have bought recently has less RAM and Flash memory than my old Linksys WRT54G V1.1 router. In addition, it is using the VxWorks OS which is not compatible with 3rd party firmware. This makes the upgrading procedures from Linksys stock firmware to dd-wrt firmware more tedious.
Hmmmm ... Does not feel very good. May be that explain why the firmware is so buggy.