SH4 v1.5 rsrdc problem

I'm new here so I don't know if this is in the right section but I'm having a save corruption problem.

I have sh4 v1.5 with rfb_2.0, rfb_2.0_patch23April2010, rsrdc_V575 and rsrdc_V5xx_Patch1 mods installed in that order.

I've started a campaign in 1941 in the phillipines and done two 3 patrols succesfully and everything has been working, but when I get transferred back to pearl harbour for my next patrol (Febuary 1942) any saves I make after that point are corrupted, they no longer save any markings I make on the map, and if I restart the game and try and load them I get a CTD (all the saves before then are still fine).

I have had this happen twice, after the 1st time I did I complete reinstall and started a new campaign with the same result.

Does anyone know what could fix this?