Unfortunately, the 1.5 patch has a terrible hatred of R:TW and BI together. BI, sadly, likes to drag your R:TW back down to 1.3 unless they are patched together in unison. To do this, the almighty 1.6 Patch is required - R:TW is automatically upgraded to 1.5 and BI is upgraded to 1.6. This handy dual patch can be downloaded from this location. Hope the upgrade resolves the Romans' run around issues, good luck, cheers!