Textastic 2.2 is now available on the App Store. It is a huge update:

Main new features:

• MobileMe iDisk support
• WebDAV client support
• Save several remote file locations – for example, Textastic will now remember a file's location in your Dropbox as well as on your FTP server so you can quickly upload and download a file using several remote locations.
• New Auto-Wordwrap option is enabled by default: this automatically adjusts the word wrap to fit the width of the editor (helpful when changing between portrait and landscape mode) - you can change this back to a fixed wrap column in settings
• New cursor navigation wheel - can be brought up with a two-finger tap
• Tap-and-hold on a file in the "Files" section brings up three new options: "Open with Encoding", "Open In..." and "Preview"
  "Open With Encoding" allows you to overwrite the automatically detected character encoding
  "Open In" allows you to open all files in other app without loading them in the editor
  "Preview" allows you to view images, pdf and word files etc. using the preview function of iOS
• You can now setup a password lock to protect your files and connections

• New drawing code for the editor - should be much more responsive when typing and selecting text
• Pinch-to-zoom shows zooming factor and snaps to 100%
• Supports FTPES (explicit auth SSL/TLS)
  

• New setting: soft tabs (spaces instead of tabs)
• New setting: show or hide tab characters
• In the File Properties popover you can now set the character encoding used when saving an already open file
• You can choose between more character encodings when creating a new file (for example, Cyrillic CP 1251)
  
• Line endings (Unix, Windows, Mac) can now be chosen when you create a new file and also modified in the file information popover
• Japanese characters are now displayed at full height and 68% width to make them more readable
  
• Tap and hold on selection handles is now handled correctly
• Tapping once on the status bar goes to the top of the file, tapping a second time goes to the bottom
• The keyboard only comes up when you lift the finger on the editor. This avoids bringing up the keyboard if you only want to scroll.
• PowerShell syntax definition
• Rearranged the settings screen
• New font size selection control
• Many bug fixes

Thank you for reporting this. It is a known problem with the syntax highlighter. See http://feedback.textasticapp.com/feedback/7433-syntax-highlighting-is-sometimes-wrong-with-strings-quotes-quotation-marks/

Sorry, but this is an annoying bug in a regular expression but I can't fix easily without rewriting a lot of the highlighter.