HTTP error when uploading images

Hi.

When I attempt to upload images to the gallery, when the image gets to 100% a yellow warning triangle appears which when hovered over suggests an HTTP error. When uploading images to assets the image disappears just before the progress bar gets to the end. Only on my live server though, local build still works fine. The last thing I did was enable compression via cPanel, but deactivating it hasn't rectified it.

Diagnostics..

    Perch: 2.8.7
    Production mode: Production (100)
    Installed apps: content (2.8.7), assets (2.8.7), categories (2.8.7), perch_blog (4.6), perch_forms (1.8.3), perch_gallery (2.8.6), perch_backup (1.2)
    DB driver: MySQLi
    DB tables: perch2_blog_authors, perch2_blog_comments, perch2_blog_index, perch2_blog_posts, perch2_blog_posts_to_tags, perch2_blog_sections, perch2_blog_tags, perch2_categories, perch2_category_counts, perch2_category_sets, perch2_content_index, perch2_content_items, perch2_content_regions, perch2_forms, perch2_forms_responses, perch2_gallery_albums, perch2_gallery_image_versions, perch2_gallery_images, perch2_navigation, perch2_navigation_pages, perch2_page_templates, perch2_pages, perch2_resource_log, perch2_resource_tags, perch2_resources, perch2_resources_to_tags, perch2_settings, perch2_user_privileges, perch2_user_role_privileges, perch2_user_roles, perch2_users
    Users: 4
    App runtimes:

    <?php
        $apps_list = array(
            'content', 
            'categories',
            'perch_gallery',
            'perch_blog',
            'perch_forms',
        );

    Scheduled tasks for perch_blog: delete_spam_comments (1440 mins)
    Editor plug-ins: ckeditor, tinymce, redactor, markitup
    H1: 67615acb424802b0f49ddaa8c3e8399a
    L1: 58171556e8cc89b5374107af83086924
    headerColour: #0080c0
    content_singlePageEdit: 1
    helpURL:
    siteURL: /
    hideBranding: 0
    content_collapseList: 1
    lang: en-gb
    update_2.7.10: done
    latest_version: 2.8
    on_sale_version: 2.8.7
    perch_gallery_update: 2.8.5
    update_2.8.2: done
    perch_blog_update: 5.0
    perch_blog_post_url: /blog/post.php?s={postSlug}
    update_2.8.4: done
    headerScheme: dark
    perch_gallery_bucket_mode: single
    perch_gallery_bucket: default
    perch_blog_slug_format: %Y-%m-%d-{postTitle}
    perch_blog_akismet_key:
    perch_blog_max_spam_days: 0
    perch_backup_mysqldump_path:
    dashboard: 0
    hide_pwd_reset: 0
    content_hideNonEditableRegions: 0
    content_frontend_edit: 0
    perch_gallery_basicUpload: 0
    perch_blog_comment_notify: 0
    update_2.8.6: done
    update_2.8.7: done
    PERCH_DEVELOPMENT: 10
    PERCH_STAGING: 50
    PERCH_PRODUCTION: 100
    PERCH_DB_USERNAME: pixels_longshot
    PERCH_DB_SERVER: localhost
    PERCH_DB_DATABASE: pixels_longshot
    PERCH_DB_PREFIX: perch2_
    PERCH_TZ: Europe/London
    PERCH_EMAIL_FROM: markrphoenix@gmail.com
    PERCH_EMAIL_FROM_NAME: Mark Phoenix
    PERCH_LOGINPATH: /perch
    PERCH_PATH: /home/pixels/public_html/clients/dev/perch
    PERCH_CORE: /home/pixels/public_html/clients/dev/perch/core
    PERCH_RESFILEPATH: /home/pixels/public_html/clients/dev/perch/resources
    PERCH_RESPATH: /perch/resources
    PERCH_HTML5: 1
    PERCH_RUNWAY:
    PERCH_ERROR_MODE: DIE
    PERCH_DATE_LONG: %d %B %Y
    PERCH_DATE_SHORT: %d %b %Y
    PERCH_TIME_SHORT: %H:%M
    PERCH_TIME_LONG: %H:%M:%S
    PERCH_DEBUG:
    PERCH_PREVIEW_ARG: preview
    PERCH_TEMPLATE_PATH: /home/pixels/public_html/clients/dev/perch/templates
    PERCH_DEFAULT_DOC: index.php
    PERCH_DEFAULT_EXT: .php
    PERCH_PRODUCTION_MODE: 100
    PERCH_RWD:
    PERCH_HTML_ENTITIES:
    PERCH_SSL:
    PERCH_STRIPSLASHES:
    PERCH_PROGRESSIVE_FLUSH: 1
    PERCH_AUTH_PLUGIN:
    PERCH_DB_CHARSET:
    PERCH_DB_PORT:
    PERCH_DB_SOCKET:

Hosting settings

    PHP: 5.4.37
    Zend: 2.4.0
    OS: Linux
    SAPI: cgi-fcgi
    Safe mode: not detected
    MySQL client: 5.5.42
    MySQL server: 5.5.42-cll
    Extensions: Core, date, ereg, libxml, openssl, pcre, sqlite3, zlib, bcmath, calendar, ctype, curl, dom, filter, ftp, gd, hash, iconv, SPL, json, mcrypt, mysql, mysqli, session, standard, posix, Reflection, Phar, SimpleXML, sockets, imap, tokenizer, xml, xmlreader, xmlwriter, cgi-fcgi
    GD: Yes
    ImageMagick: No
    PHP max upload size: 8M
    PHP max form post size: 8M
    PHP memory limit: 64M
    Total max uploadable file size: 8M
    Resource folder writeable: Yes
    Session timeout: 24 minutes
    Native JSON: Yes
    Filter functions: Yes
    Transliteration functions: No
    DOCUMENT_ROOT: /home/pixels/public_html/clients/dev
    GATEWAY_INTERFACE: CGI/1.1
    HTTP_ACCEPT: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
    HTTP_ACCEPT_ENCODING: gzip, deflate
    HTTP_ACCEPT_LANGUAGE: en-GB,en;q=0.5
    HTTP_CONNECTION: keep-alive
    HTTP_COOKIE: cmsa=1; PHPSESSID=f13f080c3d9f5043cb45ed5b8db21733
    HTTP_HOST: dev.pixelsmiths.co.uk
    HTTP_REFERER: https://dev.pixelsmiths.co.uk/perch/core/settings/diagnostics/
    HTTP_USER_AGENT: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0
    PATH: /bin:/usr/bin
    QUERY_STRING: extended
    REDIRECT_STATUS: 200
    REMOTE_ADDR: 82.46.93.14
    REMOTE_PORT: 50044
    REQUEST_METHOD: GET
    REQUEST_URI: /perch/core/settings/diagnostics/?extended
    SCRIPT_FILENAME: /home/pixels/public_html/clients/dev/perch/core/settings/diagnostics/index.php
    SCRIPT_NAME: /perch/core/settings/diagnostics/index.php
    SERVER_ADDR: 162.13.44.160
    SERVER_ADMIN: webmaster@dev.pixelsmiths.co.uk
    SERVER_NAME: dev.pixelsmiths.co.uk
    SERVER_PORT: 80
    SERVER_PROTOCOL: HTTP/1.1
    SERVER_SOFTWARE: Apache
    UNIQUE_ID: VWV4dKINLKAAAC8bYLcAAAA1
    PHP_SELF: /perch/core/settings/diagnostics/index.php
    REQUEST_TIME_FLOAT: 1432713332.97
    REQUEST_TIME: 1432713332
    argc: 1