The beta files for SEVEN networks are not accessible on the SEVEN beta forum. But here is a link to the files. FWIW, I have had problems with the 6437 version dropping my hotmail and yahoo accounts. I have no problems iwht teh 3518 version.
Link contents:
23.41.2897_3_z7-android2x.apk
23.41.3518_3_z7-android2x.apk
23.41.6437_3_z7-android2x.apk
23.41####_3_z7-android2x.zip <-- Megaupload
23.41####_3_z7-android2x.zip <-- Rapidshare