Can’t upload images w/ WP 2.5.1

I’ve been struggling with WP for the last 3 days, trying to upload images. I had no problems 3 weeks ago and made no admin changes, but suddenly have problems. I’ve trolled the forums and tried all possible solutions, but nothing works.

When I click “add media”, the browser screen invokes flash, goes dark, and a progress bar appears. Meanwhile the “Save” and “Publish” buttons start pulsing in the background for no apparent reason. Most the time everything just crashes at this point, however at times, if I wait a few minutes, the image uploader dialog box finally appears. I can then upload images, however at this point there is no provision to post those images into the post I’m trying to create. Instead, I get into an endless loop where I can not post, back up, close out or anything from this uploader dialog box. I have to exit out of Firefox entirely to get out of this crash. Also, I’ve noticed that if I try to launch a second Firefox session while all this is going on, all my bookmarks in that second firefox session go missing. Secondly, at this point, tabbed browsing no longer functions. Essentially at this point my web browser grinds to a halt and the only way to fix it is to completely exit out of all Firefox browsers and start over. Trying everything again, I’m only put back into the same situation.

I’ve followed the “image/media uploader problems” sticky post closely: I’ve re-downloaded and re-installed (via complete delete / add using FTP) the WP files. I’ve cleared browser caches multiple times. I’ve removed anything from the wp-content/uploads/js_cache directory. I’ve assured I have the latest flash PI. I’ve done the mod_security .htaccess file trick. I’ve installed the “no flash uploader” plug-in, which didn’t do anything.
I’ve tried to create a post with images on 3 different machines, using both Firefox 2.0.0.14 and IE7.
I’m out of ideas. Any help? Can we just have the simple HTML uploader back?

thank you