Checking \railworks folders, I found some new (date was modified) files, among others: BlueprintSchema.XML, WrapperSettings.xml, and all ScenarioProperties.xml and ScenarioProperties.xmlMD5 of all (159) scenarios of BSB (including my own) were updated (same modified date). Tested some and all working except those of Big Boy (which I was working with). There was also a empty file (nothing within) del_blueprint.bat. And my splash screen was set back to the default configuration (but Railworks.exe is still the same).
I restarted WIn7 again, re-installed the mod and worked. The del_blueprint.bat was gone (as it came, misteriously).
I also noticed that was changed the -000014+000016.bin file in BSB folder "\Networks\Road Tiles" folder. It seems they (who?) fixed something in that tile and rebuilt all scenarios of route.
In other words, some ninja played in background (with no warn) with my installation, as usual... not good

Beware!
Cheers,
Doc.
Edited later: date of (second) update that caused the weird behavior was on 21th, in fact. OP's title corrected.