Well this is what i have found on telefonica (columbia) RIM WEB SITE
Software para la BlackBerry Curve (8310) (TM)
BlackBerry Handheld Software v4.5.0.52 (Multilanguage)
Package Version: 4.5.0.52
Consisting of:
Applications: 4.5.0.37
Software Platform: 2.7.0.55
File name: 8310M_PBr4.5.0_rel52_PL2.7.0.55_A4.5.0.37_Telefoni ca_Colombia.exe
File size: 78.97MB
Please correct me if i am wrong