back when i synced my e-mail (until i ended up, eventually, with 3,500 of em!) i used to delete by one of two ways - highlighting a few screens at a time and then deleting (taking about 5 minutes each time), or go into, i believe, the windows subfolder - windows/messaging - and then delete those - i'm betting for some reason your inbox entries are not matching up with your windows/messaging items - at that point, make sure sync is off, manually delete all the items in /messaging, and then if you really want those items, well, i don't know how you do it - i THINK activesync lets you sync at most 100 items per day but i'm not sure.
if there's a particuar e-mail you could copy the contents into notes - anyway, these are my 3 cents
