Hi,
There have been quite alot of things not yet done in the 2.2.1 version.
The INVASION SEQUENCE1 is for an activation of one of the storyline sections - not yet done up. Plus, tanks are still todo indeed even at current 2.3-dev version.
(Today as of R24618).
As for uploading a certain jpg, if u did not notice, there is an additional button between this text box area u type replies and the POST button called "ADDITIONAL OPTIONS".
Open it and u are given an "ATTACH" option, where u can attach up to a 1 to a 4 attachments, max 1024KB. The file types allowed are: tga, obj, log, jpg, png, txt, diff, patch, md2, md3, blend, max, wings, zip, gz, bz2, odg, map, 7z
Yupz.
Have fun continually!