I tried to download some apps on my curve 8520, on restarting, it hangs with a white screen that "reload software: 552". I removed the battery several times to no avail. Connected to Desktop manager, saw the applications, tried to either delete the problematic ones, it tried until when it said it could not connect to the device.

Pls has anyone been able to fix this problem successfully before? I need assistance.

Do exactly as it says,RELOAD THE OPERATING SYSTEM.You'll need to download the OS of the device and flash it.
Advice - Limit the number of applications you install on it.They will either slow down tne device or brick it.

reload os as oga said.chikena

i had the one fixed by the follwoing steps:

Software For BlackBerry-« Curve(TM) 8520 Smartphone
This will install to any carrier\\\\\\\'s 8520 device by following the instructions below.

BlackBerry Handheld Software v5.0.0.1728 (Multilanguage)

Package Version: 5.0.0.1728
Consisting of:
Applications: 5.0.0.1067
Software Platform: 5.2.0.96
File name: 8520wifiM_PBr5.0.0_rel1728_PL5.2.0.96_A5.0.0.1067
File size: 125.47MB

Instructions to install, regardless of carrier.

1. Download the above OS file to the PC then install it to the PC by running (double clicking) the file you downloaded.
2. Go to c:\\\\\\\\program files\\\\\\\\common files\\\\\\\\research in motion\\\\\\\\apploader and delete the file named \\\\\\\"vendor.xml.\\\\\\\" Vista/Win7 users: In the apploader folder, simply click on \\\\\\\"Compatibility files\\\\\\\" to see the actual Vendor.xml file. Once you\\\\\\\'ve got that - simply delete the vendor.xml file there (even if you\\\\\\\'ve deleted or think you\\\\\\\'ve deleted it in the folder previously).
3. Plug in BB and double click on \\\\\\\"Loader.exe.\\\\\\\" It\\\\\\\'s located in the same place as the above vendor.xml file.

The process takes about 45 minutes to an hour depending on how much data you have to backup and restore during the process. Once it\\\\\\\'s done loading the new OS it will reboot (it may do this twice during the entire process.) You will see a screen with an hourglass or status bar for up to 20 minutes at a time while the DM says \\\\\\\"waiting for initialization.\\\\\\\"
If, for some reason, you end up with a white screen with small icons and the number 507, simply connect to the PC again and run Loader.exe again and it should load the OS to the device.