Official OS 4.5.0.110 for Pearl 8110 and 8120 from AT&T,

Software For BlackBerry® Pearl (TM) 8110 smartphone

BlackBerry Handheld Software v4.5.0.152 (Multilanguage)

Package Version: 4.5.0.152
Consisting of:

• Applications: 4.5.0.110
• Software Platform: 2.7.0.90
• File name: 8110M_PBr4.5.0_rel152_PL2.7.0.90_A4.5.0.110_AT&T.exe
• File size: 96.83MB

Note: The Software Platform and Applications version numbers can be found under Options-About screen on the handheld.

• Download

Software For BlackBerry® Pearl (TM) 8120 smartphone BlackBerry Handheld Software v4.5.0.152 (Multilanguage)

Package Version: 4.5.0.152
Consisting of:

• Applications: 4.5.0.110
• Software Platform: 2.7.0.90
• File name: 8120M_PBr4.5.0_rel152_PL2.7.0.90_A4.5.0.110_AT&_T.exe
• File size: 96.68MB

Note: The Software Platform and Applications version numbers can be found under Options-About screen on the handheld.

• Download

REMEMBER: Always make backups before making major changes/upgrades/downgrades to your BlackBerry.