jadeblackhawk: My warrior is at level 16, with a 66 strength, and a 2920 weight limit.
When you mouse over Strength in the statistics window it should say +26 damage / +1320 weight. If I add 7 stat points to my character with 66 strength at level 16 (though character level is irrelevant), and apply them (and close / re-open the stat window) my weight limit goes up to 3060, and the mouse over stats go up to 29 / 1460.
Intelligence should increase magic, and constitution vitality, as soon as the points are applied.
You could try starting a new game and use
iZakaroN's SaveEditor to give the character extra stat points and see if this is an issue there (they'd need 1,360,000 experience if you want to get them to level 16 as well).
If you wish you can zip your save game folder and email it to me to look at (raze@larian.com).
Each save is a separate subfolder in the '..\Divine Divinity\savegames' folder.
In Windows Explorer you can zip a file or folder by right clicking on it and selecting 'Send To | Compressed Folder'.